Annexation is nothing more or less than a boundary adjustment. The territory included in the annexing country after the boundary change becomes just like everywhere else in that country and all residents of the area newly included in the boundaries of the annexing country automatically become full citizens of the annexing country with no exceptions.
Thr confusion stems from the fact that Israel did not do this when it passed the East Jerusalem Law or thr Golan Heights Law. Thus they were not annexed and are not within the *de jure* borders of Medinat Yisrael.