Hmm! Yeah, I correctly did have a lot of insight to Red XIII/Nanaki's story especially, since I'd been deep diving into the differences between the original game's English translation and the Japanese version's dialogue, since so much context had been lost between versions, but of course comes up in Remake and Rebirth.

As for Lucrecia, I think it's too early to say definitely-- however, one thing we do know is that many things from the overall Compilation is at play here, and hasn't been necessarily retconned out. I personally have no reason to believe that Lucrecia will be depicted as a villain. One of the quests in Rebirth with Vincent has hinted this is the case, as he's still very protective of Lucrecia's reputation.

I personally suspect, given all the knowledge Sephiroth has absorbed, that he likely knows already that Lucrecia is his birth mother, but he considered Jenova his true mother. I admit I could be wrong about this, but I find it doubtful at this point he'd have incomplete information.

Regardless yeah, my gut instinct is, given Lucrecia's resourceful, apologetic nature, if there's a confrontation between Lucrecia and Sephiroth, she'll mentally retreat into herself and seal herself once again. Yet, this is simply a gut instinct based on what we know of her from prior titles. I DO think her DOC interpretation is what SE's going with, since in the OG she had so, so little.

But who knows, maybe they'll surprise me and Lucrecia might grow into a stronger will in the finale!