It is also a question of spin up time. If the demand suddenly existed to rebuild satellites en masse, the lead time on labor resources is part of the total time to rebuild. It becomes concerning if and only if either a) for strategic reasons the time is inadequate, or b) the lead time requires generational training efforts, e.g. college programs, national initiatives, etc. which can't behave predictably in response to an emergency.

Broadly speaking, sure. But you’re not trying to rebuild every single one. At this point you’re in a war, things move faster, and there are a million unknowns. Under the given scenario, it appears that satellites have lost their usefulness akin to tanks in Ukraine. It’s not a matter if you can build satellites, merely if you can stay ahead of your adversary. At present the U.S. can launch more and faster mass to orbit. I’d be more concerned about that than anything else in the provided scenario.