Should Larian keep a short-rest + short-rest + long-rest system.
I'm fairly sure they won't.
Considering that Divinity has never been based around "Spell Slots" and "Per X Rest", there would be literally no reason for them to use a rest system at all.
Since that's the primary reason for its existence in D&D, it exists as a method to limit resources. While Divinity has always lacked such a limit (Which is preferable in my view, I've always hated D&D's daily limitations especially when it always makes low level casters feel absolutely awful to play)
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.