Considering that Divinity has never been based around "Spell Slots" and "Per X Rest"
At best I could maybe see them shoehorn in a long rest system, if they decide they liked the whole "Camp" thing and wanted to produce a way to trigger interactions again.
I don't personally consider what Divinity "did before" particularly relevant in this case, but even putting that aside, "Spell slots" and vancian magic are not the only reason to have a rest system in your game/ruleset.
Especially if you are going for a coating of "world simulation" (which personally I think every good RPG should at least aspire to, as "immersion/simulation + narrative + engaging gameplay" is what I'd consider the sacred triad of the genre).
You can simply have a fatigue system, for instance. Especially if your game involves a world map, passing time and various forms of long distance traveling.
Plenty of games in the past included one without using the D&D ruleset.
But yeah, as I said I absolutely DO NOT expect Larian to go there. I'd be just happy with the day/night cycle, which is what this thread is supposed to be about.
