I think there is a fine line in Rebirth between Romantic and Platonic and the writing and depiction of both Cloud and Tifa and Cloud and Aerith's storylines do different things when it comes to the line
Strictly Romantic - Cloud x Tifa
The Line/Middle Ground - Cloud x Aerith
Strictly Platonic
What I mean by this is that there are multiple moments in Rebirth that can't be considered anything but Romantic, a nearly kiss, confirmation of "mutual feelings" in the moment, staring at them with a smile on your face whilst they aren't looking and an actual kiss between Cloud and Tifa - as well as more - are moments that can't be misconstrued, aint nobody going to believe these are things you just do with someone if they are your strictly your friend. These are things you cannot just back up on now in Part 3, because people will start to question will hang on, you had Cloud and Tifa nearly kiss, as well as kiss (even if you say dates are non canon the general public won't see it that way) and then you just dump all that like they didn't happen just to make Cloud kiss/end up with Aerith at the end, what? That would be terrible storywriting and characterisation especially with what we know are big moments coming up between the two in Part 3.
However with Cloud and Aerith I feel like they straddle the line between Romantic and Platonic enough to the point there is no moment between them that I feel like "there is a point of no return now" depicting friendly interactions between them or Cloud being upset at her death is not Romantic, and things like the hand holding and "dates" can be considered romantic obviously but then others interpret them as comforting or platonic depending on the context, or even related to Zack and Aerith's memories of him (S5 date, depending on how you interpret this, i'd love the Directors commentary on this scene) Then of course there is the one sided confession from Aerith where she herself is conflicted on if she even likes Cloud romantically or platonically, you cannot get more middle ground if you tried. It would seem to me she'd like to have the opportunity to know which way she likes Cloud but never gets said opportunity for obvious reasons.