It's public knowledge that they intend to launch a lot more satellites before that, so they are probably counting on that to help them.
Yeah, but they also want to substantially increase the number of subscribers. It seems a shame to add capacity and not users just to get a cheque from the government for hitting some arbitrary numbers. IIRC they could have bid for a lower speed target that they would probably be hitting today.
... I think they will be doing both. They currently have ~2500 sats in the ~53° constellation. The V2 system that has been approved and is targeting similar latitudes has 3 times the sats, and each sat is claimed to support 9 times the bandwidth of the current ones. So if they need to triple bandwidth per user, they can still increase subscriber count 9-fold and meet it.
I too am curious with how far they can push performance though. I've got a hunch that it has something to do with balancing satellites, users and regional coverage, but only time will tell if they make good on their promise. Even if things stay the same as they are right now though, there's nothing else that comes close in my area.
I don't think 10 people has anything to do with a single household but maybe I'm just an out-of-touch liberal coastal elite. But seriously, one person can use around 25 Mbps which is why there's discussion of defining broadband to be 100 Mbps per household.
The RDOF performance requirements are much more subtle than just average speeds though, there's details about percentiles and time of day and the like. I'm hopeful someone is being thoughtful at the FCC