Actually I think this is the worst quote in the world to exist for Cloud/Tifa, and I say this while being massive C/T at heart. So the full quote is:
There are two time periods this quote is talking about. Pre AC/post ACC. Even with the pre AC context, I think it does exist as a nasty base for Cloud and Tifa not being compatible. If the highlight of the discussion here were Cloud's traumas that existed in between Geostigma/Sephiroth, then why does Nojima choose instead to, first disclaimer, as to not include his own views of love/marriage/family, and then mull over Aerith's potential as a romantic partner instead? Aerith has no shot, for obvious reasons, but Nojima includes her because he's envisioning how Cloud would exist as one half of a romantic partnership for both women, and he isn't enthusiastic about either of them. So Tifa wins, but at a cost loaded with Nojima's personal baggage. Post ACC: I guess the kids could help them is not a fist punching win, either. Poor Marlene and Denzel.
I personally think you have to twist it out of context to rub out the compatibilty part to make it about Cloud's trauma. Nojima went out of his way to remove two massive trauma's of Cloud's life and I feel you are inserting all the other ones he didn't actively choose to omit, but that he didn't need to, because that isn't what he's talking about to try and shield Tifa away from the point of what he's strying to say. The rest of the quote still exists. Nojima doesn't sit down and say they're the couple of the decade post ACC, but rather sticks a fork in what the ultimanias and post ACC credits actually show.
Which, by the way, is still a C/T pro. Tifa has to be someone Cloud is romantically interested in/in a relationship with for Nojima to speak in this way about her. So anyone using this quote as fuel against is either, backhanding themself by admitting Tifa is Cloud's partner (which honestly, too many and too loudly of the opposite party still deny to this day) or holding it to iron and concluding that Cloud/Tifa don't work out and they are free to think Cloud thinks about his flower girl for the rest of his days.
This is what sucks about this quote, the ultimania quotes and the post ACC credits scene exist to say this isn't what Cloud does at all. The correct interpretation would be that Cloud and Tifa do work out but these developers are utter chickens. I like what someone said earlier on this board, that we have all the ultimania quotes but they can't just outright say Cloud and Tifa are boyfriend and girlfriend. Alas, two more games to go.
I've tried reading this several times but I'm not sure what you're talking about so I find it hard to really decide how to respond.
He's not talking about 2 time periods, he's just talking about Clouds issues separate from the events of ACC, which yes, start before ACC and potentially extend past it, but are still just one time period. Unless you mean the second period are the events of ACC specifically when he's talking about Sephiroth and Geostigma, in which case I agree but that's kind of the point, the issues weren't Geostigma and Sephiroth, the quote is trying to look at them separately.
I don't know where you're getting the "rub out the compatibility" part from, there is nothing to rub out, compatibility is never even mentioned, nor is it in any way relevant.
The reason he's mulling over Love and marriage is because this is a love/marriage situation, again, I don't see how this is relevant in any way aside from highlighting that Cloud and Tifa are romantic.
I suspect you're making a mistake that I often see people making, which is treating quotes as though they're hints.
People often treat quotes as "word of god", as though canon is some elaborate puzzle that the developers want you to figure out and every quote is a perfectly accurate, immaculately sculpted puzzle piece where each word was carefully chosen for us to pontificate over. It's not, most quotes are just spur of the moment ramblings that can give you a vague idea of the mindset of the person at that time. When I write something I edit and reword it a dozen times over to iron out stuff that could be misinterpreted or didn't quite come out the way I wanted it, and yet I am STILL constantly misinterpreted. Interview quotes by people who are not even shippers are about a thousand times more inaccurate.
The reason he's saying these words is simply more generic, it's just because Cloud is going through issues, and he's just kinda speculating this way and that. Who even knows what "maybe with Aerith it could have worked out" even means? Maybe it just means "ehh, maybe Aerith could have helped him get through it better since she's good at getting people to open up", which isn't any more of a testament to her compatibility as a romantic partner as my sessions with my psychiatrist mean that I should be dating him instead of my girlfriend. Or maybe it meant "maybe he wouldn't have been as messed up if Aerith hadn't died". We don't know, but no version of this quote is even CLOSE to touching on the innate compatibility of Cloud and Tifa as a romantic couple.
Same thing about the Denzel and Marlene stuff, just more "in the moment" speculations. For one Clouds issues were (mostly) solved in ACC so this part of the quote is already not very useful, and if you think that this quote is proof that the issues persevere in their current form post ACC then I refer you back to my point earlier about not using in the moment quotes as well thought out, perfectly articulated, puzzle pieces. But either way it sounds like nothing more than either a generic remark that if Geostigma and Sephiroth hadn't happened that perhaps Denzel and Marlene could have helped them work through Clouds issues (not them staying together for the kids or something like that), or else an equally generic remark about all the dozens of potential versions of this story where Clouds issues weren't solved during ACC. The entire quote is just taking Clouds issues and generally separating them from the concrete events in ACC and addressing them from the lens of a traditional domestic issue, and all of them say the same thing "Ehh, Cloud is working through mental health issues, who really knows how different events could have impacted that."
I just don't get what you're trying to say here, I see nothing bad or even remarkable about this quote when it comes to Cloud and Tifa, it's such a nothing burger I do not get why people think it's noteworthy.