That’s a complicated one. Military tech tends to all be 10+ years old at time of deployment and the ones stockpiled are probably late 90s designs that went into production in the early 2000s. Most of the parts for the control and guidance systems are likely no longer produced at all and haven’t been for a decade+ (think the kinds of computer chips you’d find in a SNES, maaaaybe an N64) so it’s not that they don’t have the blueprint somewhere, they would have to re design large parts of it to work in a modern supply chain. Yes, they could do emulation/simulation shenanigans to get some stuff to be compatible on modem COTS hardware but they’d still need to re qualify everything because nobody wants a 500lb ballistic warhead going stupid and killing someone in the wrong country.

They might not.

There’s been a couple cases where the US military has classified something so heavily that they needed to re-spend millions in R&D in order to learn how to make the material again.