I'm saying this as former US military here. the Idea that in the middle of a OPORD, of any kind, POTUS would come in last minute and change a detail, like an explosive on a timer (fairly simple,) to what is effectively some new technology no one has ever heard of, that allows for remote sonar detonations is Tom Clancy stuff.
In the United States Military, there's this thing called the Chain of Command.
This exercise was under the U.S. Naval Forces Europe-Africa, which is under the United States European Command & United States Africa Command.
The "work" that being described here would have been under SOCOM (United States Special Operations Command), which is the only command that could do this kind of work, they are the only ones that even have the assets to do this kind of work and theres absolutely no mention of that in this piece.
It's complete conjecture and should absolutely be treated as such until theres hard evidence.