Ok, so looking into it, WOTC owns the D&D license, which Larian Games had to licence. So, yes it indirectly supports WOTC. They don’t own a stake in the game studio, and therefore aren’t directly getting revenue from this games sales. They have already received the licencing fees they would be getting for this game. It does however help WOTC since they aren’t developing their own 6th edition games currently and keeps D&D relevant so in that way it does support them.

Personally I would find that a morally grey area, and will pirate the game to see if I will buy it on sale.