It is VERY easy for any Arab resident of East Jerusalem to get Israeli citizenship. Ministry of Interior is required to grant them citizenship by law. Tens of thousands of them applied for and received Israeli citizenship. Of course you have to apply while you are still a resident, not when your residency status was revoked after 20 years of absence.
Dozens of Zionist Union activists call on Netanyahu to resign in Tel Aviv protest (Haaretz)
from the article: The silent expulsion