When TOS Remastered was produced, the mandate was to not tweak the running time of the episodes, nor affect major changes to the audio. I don't see any reason why TNG would be different in this regard. Any audio work would be negligible.
With the original ST, they didn't have to re-edit the entire episode, so therefore they didn't have to make major changes to the audio.
With TNG, because they'd have to reassemble the episodes from the original shots on film, they'd most likely have a LOT of work to get the audio to match up.