I love larian, but this is just marketing speak. There won't be that many different endings, they probably include every permutation of every character being alive or dead at the end and stuff like that.
Knowing Larian they're probably referring to all the different possible combinations of each party member and side quest endings that each get five words in the outro like in Fallout 3 and FNV. Divinity Original Sin 2 has conditioned me to expect big promises about scope to be followed by a mile-wide, inch-deep game where you get softlocked if you deviate from the main quest line's invisible rails and the "multiple endings" are all functionally the same ending.