David is kind of fudging on that. He wanted a major setback, but what he produced would have been the collapse of the economy and at least 10 years of time lost. (When your average design engineer and most senior tech has exactly as much experience in manufacturing as the guy you hired yesterday to sweep the floor it's likely that your first products will have 'issues', and so will the second and third) When nobody is building anything, all the people mining materials have no customers.
And the RMN would have actually taken significant steps to ensure that it remained combat capable as long as possible, as without any spare parts things that wear out or break will be down until some vague date in the future. So readiness will inevitably drop over time, and it will drop faster when you inflict more wear on the ships by doing stuff. Notice that nobody has any worries about where their spare recon drones will come from, or particular focus on recovering them.
I suspect that if he finally talks about the impact in a later book he will have backed off from the comments he made here. But we will see.
