WotC rejected Larian's application for the license before DOS2. That means they have some standards for how faithful the adaptation will be.
You make quite an assumption there as to why WotC didn't give Larian the licence to BG3. If WotC was concerned about faithfulness of Larian's adaptation of their system then they would put it in the contract. There is no indication as far as I know that WotC is in any way unhappy with the direction Larian is taking the game. If anything D:OS2 convinced them that Larian was the studio to make BG3.
