Another 6 flights planned this year. Whilst the booster didn’t make a success burn it landed where planned and the Starship re-entered where planned, so I can’t see a need for a further FAA investigation and licence renewal should be routine.
The failure of the engines to relight for the booster landing will have been fully covered by telemetry and I foresee it being resolved for the next flight.
The Starship is more moot. SpaceX has landed Falcons but never from orbit. Their capsules are totally different from the Starship and, even if enough telemetry was gathered, it might need major redesign across the board in heat tiles, flaps, payload door or even internal structure. The 8nternal investigation and and modifications will be the timing factor for another landing attempt.
There are other upper stages that can be tested of course - such as tankers which are not planned to be recovered as well as prototype lunar landers.