SpaceX received a CCSC-2 agreement to work on an “integrated low Earth orbit architecture” involving both its Dragon and Starship vehicles. “This architecture includes Starship as a transportation and in-space low-Earth orbit destination element supported by Super Heavy, Dragon, and Starlink,” the announcement stated.
It looks like this is the first official mention of a Starship station.
Eric Berger also said:
At the time, IIRC, the speculation was that SpaceX really phoned in their Commercial LEO Destinations bid. Berger makes it sound like they might have withdrawn?