This sounded off to me, but maybe everything does. Another off-sounding idea I've heard: Gillian Tett, an editor and columnist at the Financial Times, seems to think there's a good chance Trump wants to hyperinflate the US dollar so he can somehow set more favourable repayment terms, when time comes due for them to renegotiate. I expect that would lower their credit rating even more but I guess Trump in that scenario doesn't care about that.
Normally I'd say it's possible for people who have been through failure (in his case, bankruptcy) to know things that more successful people don't, but whatever logic he has is overruled by his apparent narcissism so it's hard to be sure if what he thinks he's going to accomplish has some basis in reality.