Elves in previous Divinity games also didn't look like they were literally tree people and they didn't have horns. It's like Larian goes out of its way to deliberately wipe their minds out of all previous continuity between games.
Just pretend that these are Dryads which are calling themselves Elves.
Keep in mind the huge gulf of time. I believe there's a good 1,000/2,000 years in there since D:OS 1. I'm sure/hope by release the intro will highlight that.
Though, your quip about dryads might justify the whole cannibalism thing. :P
