Eerie
Fire and Blood
See, in Tifa's date, you actually see Cloud wanting to know what Tifa wanted to say; so for the player, the flow is simply better to understand why he says "only what you say matters" and why she chooses to remain by his side in Mideel. If you don't go through that, those two moments fall flat and you may end up really resentful towards Tifa that she leaves the group at such a crucial moment (many did, in fact, not like that Mideel scene; it takes more time annnnnnnnd a better translation to understand her).If Tifa was trying to confess alone then I argue that it's even less necessary to get her scene. I already had realized by that point she had feelings for Cloud by the time I got to Mideel so I didn't see it as strange she would pick Cloud there. I was pissed she hadn't told him the truth but I understood she loved him and later on it made sense why she had not told him.
Tifa's words before Cloud falls in the reactor, her jealousy in the Shinra building, her waiting for Cloud in the Shinra building by the elevator etc. all those moments made it clear she had feelings for him.
As for Aerith, you say you can figure out the connection between Zack and Cloud from Gongaga. I really don't think it's the same. That's about her feelings for Zack sure and the mystery that he went missing. But not really connected to Cloud himself.
In her date she literally says she's searching for Cloud as a hint that Zack is connected to his identity issues. Something you just don't get from Gongaga. Aerith's date is not just about her feelings. And yes the Lifestream scene reveals it was Zack in Nibelheim but no where is it mentioned that Aerith's attraction to Cloud started from being reminded due to similarities with Zack which is the connection between Cloud Aerith and Zack and clears up the narrative there even more. It does close her arc I agree, but also without it I feel it's a bit of a gaping hole in not just her arc but for the connection with Zack. We get told Cloud heard the story from Zack and made illusionary world but Aerith basically tells us the extent of that: he did that to the point their mannerisms were the same.
Edit: It just also feels a bit anticlimactic and empty without this "I want to meet you" reveal where she admits her feelings on the similarities. Without it if feels like Zack's some random dude she once dated who she thought left her for another girl according to Gongaga....okay but why do we care? Her date is basically the answer on why we care.
It also is important to clarify her motivations. It explains why in the beginning she basically locked Cloud in her house and took the long way to stall him and ask about Zack. Without her date you never really get an answer other than "Oh well I guess she liked Cloud?" But there was clearly more than that there.
I'm not saying Tifa's date is not important in terms of her own feelings but in terms of missing information I definitely think not getting Aerith's date in OG does leave a giant hole in not just her story but part of her story with Zack. Edit: Even if you can figure it out without it's still feels a bit lacking and empty without it also she wouldn't get an arc resolution.
Also Gongaga in OG was completely missable so even more so. Zack in the LS would have come out of nowhere.
I don't see the OG dates as just fanservice. At least not Aerith's and Tifa's. That's just my own thoughts. However as I said they definitely changed it up for Rebirth.
Edit: clarified my point. Disclaimer: Also I'm not arguing Tifa's OG date is completely useless either in case anyone wants to twist my words to put her date down. I'm not doing that.
It's obviously important to her arc and doesn't contradict anything and it fits continuity. I just don't think you're missing out on crucial information if you skip it because her feelings for Cloud are kinda shown throughout. Whereas Aerith's arc feels weird and unresolved without her date.
And yes I agree that Aerith's date is important for her own arc. But I don't feel it's that important to understand the story as a whole. I think there are way more obstacles to that (aka the really bad translation) than missing Aerith's date. You know back then I hated both Cloud and Aerith so that date was really a CHORE to me lol. The play didn't end well xD
I don't think it was ambivalent because she already questioned his identity.As for "what" Tifa is trying to confess, it is probably meant to be ambivalent. Just like Aerith's date, the romantic atmosphere makes the player focus on the romantic feelings of the girls, but later reveals will force them to add up also a deeper reading as regards Cloud's persona: "so that's the nod between Cloud and Zack" / "so that's why Tifa was reluctant to speak openly with Cloud".

Why would she bring it again? This simply doesn't fit. Tifa's date is the 100% romantic one because she is the real love interest, that's what her date is signaling. And also that Cloud is interested in her. If I had had her date in my first run, maybe I would've understood why she stayed back in Mideel. But with Aerith's date, all I got with that was the ToA with freaking Cait's reading CA, and then Aerith's death which I wasn't sure wasn't going to be made into a "lover lamenting the loss of his love" type of thing once Cloud would be back. So yeah drop this arse Tifa, wtf are you doing was my exact reaction because those were the informations I got from a game that wanted to make me really believe in that poor love story (Cloud was an arsehole period).
To understand perfectly the game and why it goes that way, you HAVE to have Tifa's date. YES I agree you have to have Aerith's date too to understand HER arc but that's the OG problem, it's that it assumes that you replay it several times when most players stop after Disc 1. And it shouldn't push you that hard into thinking CA is the romance pair because what you miss is important for the comprehension of the game. I truly think that the Remake trilogy, at least, is good on that point because it pushes CT as the romantic pair and makes a lot of people actually understand that side of the story. And yeah, you still see the most theorycrafters newcomers actually understand what's going on. Yes someone theorised that Aerith was attracted to Cloud because of Zack, before even arriving in Nibelheim. So now with the 4K it's completely possible to understand the story even without Aerith's date. But the trilogy also really wants you to watch all the dates to fully understand the relationships Cloud has with the others, and made it easier compared to the OG.