I think the DIA is correct. They likely know of the compromised people at the CIA/FBI/DOJ so military intelligence can protect him much better.
A U.S. official familiar with intelligence reports said the reported defection is false.
Two other government sources said they do not believe Mr. Dong defected, but declined to say whether U.S. intelligence agencies may have a high-level defector from one of the Chinese spy services.
https://www.washingtontimes.com/news/2021/jun/24/defection-rumors-coincide-chinese-communist-loyalt/