Think about it though… I’m bad with geography but aren’t TX and NM not the same state and so your niece and this guy were using a lot of FaceTime and such. And that was okay when he was located in Texas but not when he’ll be located somewhere else, the most obvious explanation is someone is going to be with him.
Ron’s explanation isn’t impossible but context matters. Did he do the breakup very kindly and say it’s best for both of us if we go no contact to avoid hurting each other? Is he a kind and considerate guy? Did this not come completely out of the blue?