The modding community is hard at work doing stuff for this game. One of the neatest things I've seen so far, is that modders have gotten all seven characters playable in battle at the same time. So no more of the normal 3 party, but everyone else hangs back - you can get the entire gang in there issuing commands and going ham. Which is kinda mind blowing that the game can even support that, but it makes sense that it's possible considering it's rendering them all to begin with.
Given how the final fight against Genova is in the original game where you can throw multiple parties at her, I'd be willing to bet that the final boss gauntlet of Part 3 will have at least one part where the whole party is fighting and can be playable at the same time. If they don't do that, it'll kinda be a lost opportunity, or something that the base PS5 hardware just can't manage.
At the very least though, I'd be willing to bet that we'll still get a multi-party battle in some form. Rebirth kind of already did that, but the numbers line up perfectly to have 3 separate parties of 3 each. (Since, sans Aerith, there are 8 party members, plus Zack now.)
Also also wik, considering the abstract of expanded combat parties, imagine an FFIX or VI remake where you're using a similar combat system but you can roll around with 4 dudes on the regular.
At the very least though, I'd be willing to bet that we'll still get a multi-party battle in some form. Rebirth kind of already did that, but the numbers line up perfectly to have 3 separate parties of 3 each. (Since, sans Aerith, there are 8 party members, plus Zack now.)
Also also wik, considering the abstract of expanded combat parties, imagine an FFIX or VI remake where you're using a similar combat system but you can roll around with 4 dudes on the regular.