What the audience grew up with isn't a factor.
There is no guarantee that all the systems that came with Hashino in P3~P5 are here to stay going forward. With new directors comes new direction.
That's part of what made P3 so exciting back then and that's part of what makes P6 so exciting now. Many things we've come to know or expect from Persona can change. Pretty drastically, in fact.
I said all that to say, Persona's existing identity won't impact P1/P2 remakes or remasters.
As far as Persona 2 goes —
They'll basically handle it the same way any other developer / publisher has handled a duology. If it's worth it to remake them, it'll be mostly 1:1, and it'll be handled the same way the Persona remakes on PSP were handled or the way SEGA handled Yakuza Kiwami 1 & 2.
If it's not worth it to remake them, they'll be handled closer to the way SEGA handled Yakuza 1 & 2 HD or how Falcom handled Zero/Ao no Kiseki Kai. Remastered with touch-ups and some quality of life improvements.
Or they'll remaster and port over the existing Persona 1-2 PSP remakes.
Either way, there is precedent, and they won't be pulling any FF7R shenanigans. What we get will be close to the P1/P2 experience we already know.
The idea of P1 and P2 coming in the future isn't far-fetched or a unique challenge or anything.
So, if it's something you're looking forward to or hoping for, I wouldn't worry. 😊