Clone is definitely not a word I would use - there are too many diferences on design, technical, and tone level to make them seperate IP, but yeah, I think it is closer to D:OS2 then BG1&2, and that's where I think a lot of disappointment comes from.
Even if Larian bases a lot of BG3 on D:OS2 it is not a copy-paste job. Perhaps they saved some time on finding new voice and fun, but they are still building a game with more of everything, so the dev time is understandably longer. Also D:OS2 felt rather unfinished in its later staged, so lets keep fingers crossed that BG3 will avoid that fate.
Not the clone, no. Reskin I believe it's usually called.
An extreme example of this, I'd say, are UFO 1 and 2 (the original ones from Microprose, not the recent remakes by Firaxis). Apart from very minor changes (like 2-level maps), literally everything in the game is absolutely the same, only renamed and re-drawn.
With BG3, there's clearly more difference in the most important part of the engine which is visual / cinematic, and the rest is... renamed and re-drawn?
