This is fake news. Any US citizen with a legal domicile and/or voter registration in a US state, who is not barred from voting by that state, can vote for federal offices. There are no actual federal elections, there are only state-level or district-level elections that determine the makeup of the federal government. If you can vote in South Dakota and you move to Guam, then you can no longer vote. If you move from Guam to Washington D.C., then you can vote again, but only since relatively recently (DC residents originally couldn't vote because it isn't a state).

Who can and cannot vote | USAGov

Can you vote in federal, state, and local elections? Learn about qualifications such as citizenship, minimum age, registration, and more.