Xiden will likely stay in office, even if Georgia is decertified, if for no other reason than that he will still have 290 E.V.s.
PING!
What happens if Arizona and Michigan does the same. What would the count be then. Does he need Pennsylvania and or Wisconsin also.
You are correct. The President of the United States is elected by the Electoral College, not by voters. There is no mechanism to "decertify" the vote of the Electoral College. Depending on State law, other offices might be subject to decertification resulting in an office be declared to be vacant. Then the law and procedures for filling the vacant seat would apply.