I wouldn’t say it shows it’s possible yet. They claim it’s possible but there are none of the starlink v2 satellites in orbit that are required for it to work. Originally v2 satellites required Starship for launching, it sounds like they are pivoting to Flacon now though due to delays in Starship reaching orbit.
Apple will want the service to be available as soon as the Phone launches, so potentially in late September. It’s going to be at least late 2023 before the SpaceX/T-Mobile service lunches.