Just how long can Boeing milk McDonnell Douglas products?
As long as it is needed and no suitable platform is available.
The A-10 is still doing great work and if Fairchild was still around, I imagine they would be producing more Hogs.
The F-15/F-15E are terrific jets with capabilities that are still viable and lethal not appropriate for open discussion.
Spiral development and enhancements and modifications and upgrades make the jet quite capable for. . .who knows hos long. . .and weapons are evolving all the time as well.