I think the opening of the "This Time is Different" section is a bit silly and just rings of the all-to-common Trump Derangement Syndrome.

Trump is the most immediate threat to the dollar's reserve status, but not for those silly reasons. His beloved tariffs directly reduce the flow of dollars to foreigners, which is how reserve currency status is maintained. He's trying to use bluster and threats to offset that, which, at best, is a short term solution.