Yes. And unlike foot soldiers, and to some extent tank crews, pilots cannot be replaced in a few weeks, or even months, if you want them to be halfway competent in operating a complex weapons platform. Then again, given the number of pilots who have “accidentally” dropped munitions on Russian towns, “competent” seems to be relative. The alternative explanation is, of course, that the pilots knew what would likely happen over Ukraine, and did the prudent thing, “losing” their ordnance before flying into range of Ukrainian air defence, and then returning safely to base.