Sequel or not, you always have a better chance of enjoying a new game if you don't approach it with a list of features it must and must not have, but a willingness to experience it on its own terms.. Whether BG 3 will feel like a "real" BG game is likely to depend largely on what appealed to you in the originals--and that clearly varies from person to person.
This close to early access it seems to me to make the most sense to wait until you've actually played the game before making broad pronouncements about what it is and isn't--and to remind ourselves that "The Truth"on the subject of BG3 vs. DOS3 will inevitably be a personal one.
