It’s a tricky one, but I agree with Hal9000 that looking forwards is key. If there’s (say) a 99% chance that all the frames have now been found from the various 4K prints and UHD/Disney+ editions AND everyone is on board with switching to the new sync format, then I think it’s a really good idea. It would be a nuisance for a short time for the audio people to convert GOUT-synced tracks to the new standard, but afterwards there would be a new “gold” standard for all projects going forwards. (And in the future, the old GOUT-synced tracks would still be available for “legacy” projects such as Harmy’s current DE v2.x editions.)
However, if new frames are going to continue to be discovered every couple of years (*) OR different groups are going to adopt different sync standards, then things will get terribly messy and we probably would be better off just sticking with the GOUT standard.
(*) It is extremely unlikely that there are any more frames out there to be found, according to Team Negative 1.