Well, here's the thing, DMC5 was obviously shipped incomplete. You could see lag on one of the levels (the long tube), PS4 could handle all the action, but not with online enabled. They also omitted multiplayer - remember that? There was a rumor going around that Bloody Palace was going to have multiplayer, but I guess it was gutted during final phases of development.
So, when I look at DMCSE, I see they're adding more modes to the existing package. I said "multiplayer" to the horde mode. If PS5 can push that many enemies onscreen at once, there's NO EXCUSE why there shouldn't be multiplayer.
I have a feeling that they're building up to a complete edition to sell physical. Most games are currently $70, sometimes $60, but Miles Morales is $40 because it's basically a Spiderman expansion, not a full sequel.