You said — “It’s a spy ship, not a minesweeper, and that’s according to the USN.”
Well, I think it was a minesweeper by “design” (as it was originally made and thus an apt description), but it was engaged in intelligence gathering operations, dragging a sonar unit designed to track Chinese submarines....
So, you could say that either term fits what was happening. It’s a proper description to say it was a minesweeper and also, the article does make it clear that it was engaging in intelligence gathering operations.
It was originally designed for this purpose only. The older SURTASS ships were monohulls.