IMO it's more likely that they're a very carefully orchestrated piece of "deterrence theatre" on the part of the USA. It's not outside the bounds of possibility for the US to have some kind of "trump card" technology that makes building UAP like things possible.

Now imagine you're a nation state with that kind of tech. You actually WANT your adversaries to know you've got it, otherwise it's a useless deterrent. But at the same time, you don't want them to know too much about it, because they could copy it.

So something like UAP's should be the excellent model for how to disclose their existence.

Havana Syndrome is like how cops are dropping dead from contact with fentanyl. Except cops aren't doing that, and Havana Syndrome isn't real.