How's that supposed to work if there's both an East Frisian America and a Ragusan America, or some such? Only one can turn into USA and the other will forever be a colonial state?
Suppose East Frisian America forms the USA I'd imagine that Ragusan America could still break free from their colonial overlord but would still be called Ragusan America. I'd also imagine that East Frisian America wouldn't necessarily be able to take the USA decision unless they own so much of that region that Ragusan America is basically a footnote. Just speculation, though.