Usually when the KLC changes, there are existing parts which fall foul of the rules, as well as further changes to rules to allow for unexpected exceptions. The rules on component names don’t matter much currently, but probably will when the new symbol file format is implemented similar to footprints (names must be a valid file name).
Unfortunately changing names causes chaos with existing designs, but I think that boat already sailed
Everything that is done after the 4.0.7 tag will be released with the v5 release only.
We plan a major overhaul of the lib organization anyways.
So i don’t see a problem here.