You know, the problem here is that in order to re-do TOS they simply make new versions of certain shots, of exactly the same length as the originals, and insert them into digital video of an episode that's been through the whole post-production process.
That is, all the footage and sound effects and elements were completely assembled into an episode decades ago.
TNG's raw film footage was transferred to video before
postproduction. It was assembled into episodes on video.
Basically, to recreate a TNG episode means to do all the post-shooting work again
. To use the original soundtrack means to match every shot precisely
from the original version to the new version.
Even if all the raw film footage exists, it's probably only doable at all
if every bit of editing was documented and all that documentation exists in useable form. It would be a daunting and expensive task to do one or two episodes, much less 178.