I believe what you are describing is a lot of cost with no more benefit for the generally-unlikely scenario of "dead satellite might be recoverable" than what t

I believe what you are describing is a lot of cost with no more benefit for the generally-unlikely scenario of "dead satellite might be recoverable" than what they're doing now: porting software forward on-the-fly. The issue is too rare to have always-running process for at nonzero cost. Satellites don't really "go" anywhere, generally, when their orbit is known (along short timescales). If porting takes a few days or a month, they'll still know where the target is when ground control is ready to talk to it (especially since they can track it without needing to forward-port the control software).