So if im correct, as a long time PS player, im pretty sure what they mean by compatiblity in this sense is mainly to the account system inplemented into mpst of their games. Their system differs from XBOX where games recognized and saved data soley on the Microsoft account, which is why name changing is pretty much flawless. Whereas Sony has always had games recognize and save data via the PSN ID (good example is games like CoD, you cam search a Microsoft account and get stats on a player, but only search player ID to get stats on PSN players)
While it is a little bit of an upset as we won't know the list of "compatible" games released before April of 2018, I am still very excited to change Kid_Chester to my current name.