The only way I can reconcile this is political constraints - perhaps they can't feasibly do what the GP proposes, but they could assign HLS to Starship and have some idea on how to capitalize from it "unexpectedly" exceeding expectations.
But then, I know nothing about how NASA operates internally.
NASA has taken a cautiously optimistic stance on Starship. The assignment of the HLS to Starship and no other provider was an aggressively optimistic stance from NASA that surprised many of the space industry observers at the time of its announcement. The expectation (and normal NASA behavior) would've been two assign the HLS to multiple vendors, at a reduced funding level and stretch the timelines out.
So, I'd argue that NASA is already being quite bullish on Starship given the projects and funding that they have available.