Keep the game as-is. For them to make such a huge change in development at this stage of the game, we'd lose too much content or have it delayed 2 years. There are many well made games in 3D isometric that most modern games cannot live up to.
It would not be delayed for 2 years just to add in rotation....
Not that I could care much for it. Divine Divinity didn't have this feature and it was fine. It's simply that this looks similar to NWN rather than to Baldur's Gate so I thought it would have a similar camera maybe too.
Imo the game looks more similar to Torchlight than to NWN, and the isometric view worked well in Torchlight. Also in NWN you didn't have a party, having to rotate (and tilt, and zoom) your camera to get an optimal view every time you select another party member is seriously tedious (NWN2 is a very good example of this) and it really doesn't add anything to a game that was designed with a fixed isometric view in mind (and I rather that not be changed).
The only game that I've seen that managed to combine both to a satisfactory degree was Dragon Age: Origins and I'm pretty sure some serious thought had to go into the level design to make it work well, adding such a system retroactively is probably not feasible.
