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.