Personally, I thought the animation was crap. Sorry, but that's just my opinion. Most TV animation in that era was - don't start me on the Transformers and other such shows.
I'd be delighted with a complete re-do of the visuals. With the amount of space on Bluray discs it wouldn't be hard to include both versions to keep everyone happy.
With the wealth of recordings of the cast 'in character' to sample (I'm including TOS) it wouldn't be too hard to put a few new episodes together, licensing issues notwithstanding...