Put it this way - animation is costly and time consuming. Cheaper animation looks, er, cheap.
CGI will continue to get cheaper, especially when used with motion capture. Take the copious amounts of telesnaps, map them into 3D, use motion capture suits to insert the actors and you are there. The very next best thing to finding the episodes, and within a few years, affordable.
If they wanted to, they could probably finish the Baker Shada now...
And before you know it - Holodeck versions!
I do think in the case of such animations they don't need to be in much of a rush. Indeed, the longer it's left the cheaper and better it should be.
But none of us, or the talent involved in the originals are getting any younger.