Well to be fair, that's just an engineering problem for Saudis. They just need to retool and they could use those weapons just fine against US or Israel.At end of the day it's objective reality that none of Saudi Arabia's US supplied modern weapons will work in a conflict with Israel, e.g. their F-15s would be unable to target Israeli jets assuming they can even take off.
It would be a trivial thing to do for most major countries, maybe even middle powers like Iran or Ukraine.
That said, it's Saudis you're talking about. Theyve become lazy. The issue isn't revamping F-15, the issue is the mentality in the population not lending itself to struggle.