Sony has confirmed that it has changed its protocol for handling potentially unsuitable PSN ID usernames.
In the future, PSN IDs that are supposed to violate the ToS of PSN will instead be swapped for a temporary wildcard ID with the word "TempXXXX" (Thanks, Gamasutra). Players can then choose a different ID or return to their old one for free (assuming this name does not violate the new ToS).
Keep in mind that PlayStation has put together a long list of tested games that may have problems with accounts whose names have changed. Some are listed as "problems" (your old name may display, PSN accounts may be disconnected from in-game accounts, game settings may be reset), and others are classified as "critical issues" (you may lose currency in game, Progress and / or user-generated content).
Around 40 tested games fall into this first category with "problems" – games like Killzone Shadow Fall, Assassin's Creed 4: Black Flag, The Last of Us, Titanfall 2, Warframe and PlayStation VR Worlds. Only 10 games fall into the category of "serious issues": Everybody's Golf, LittleBigPlanet 3, Disc Jam, Just Dance 2017, Onrush, Worms Battlegrounds, The Golf Club 2 and MLB The Show 14, 15 and 16.
Learn about the changes, including updating your own PSN ID (definitely a non-offensive one).