Sorry, this is an interesting idea
theoretically, but I think it's not very practical solution:
First of all, there are hundreds of published realtracks, each one with several associated, loooong audio files. Correcting chords for all that material means A LOT, REALLY A LOT of work, probably thousands of hours.
Second, there will probably be still a lot of mistakes on the resulting SGUs. It's not always easy differentiate between, say, a Bm7 and a Bm9, even for great musicians, specially when you have been checking chords in front of your computer for hours.
Don't get me wrong, it will be great to have a list of chords supported be each and every realtrack as suggested here:
https://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=480240&gonew=1#UNREADPGMUSIC have already this information and shouldn't be very difficult for them to publish such a list if they want to.