So, these refreshes we already know are free updates to past content, but if you are asking what we would do... It really depends on the details.
Now, I do think many people would complain about paid upgrades. That is as DLC for DLC as you can get, which seems to be the soapbox I see stood on most often. It may still sell well like MFP, though. DLC for DLC does not really bother me as a concept in of itself, and Sims 4 is not exactly trailblazing the concept either.
However, it really comes down to content versus price for which I would prefer. If paid upgrades fixed all my qualms with the packs I have issues with, then obviously I want those and depending on the price I might just be happy to have them with all past negative feelings put to rest. I would also obviously want those upgrades instead of new packs I am not interested in, but that is the thing: we won't really know until we get it.
As for bugs, they're 100% coming either way. New or reworked or whatever. There is absolutely no reason to think that paid upgrades will be any less buggy than base game updates or new packs. So no reason to prefer one or the other there either.
