I'm assuming by 'split' you mean 'available on both'?
I wonder if there is a way to maintain your saves across games they'll implement in some way. If they do progress saves towards new episodes, then will they allow that cross-platform? It'd suck getting all the way through episode one to discover PS5 is releasing and cross-platform saves won't work so if you want to play the rest of it on PS5 you'll have to buy it and play it all the way through again.