I find with Roscoe, there's always a context you need to have to really parse his statements. He pointed this out himself early on the interview.
As an aside, I thought Andy handled this interview really well. He pushed Coulthart a little without "calling him out" and ended in a collegial way, ensuring we'll hear them both together again.
To get back, I think he was talking about a few things at once here. I think if you pressed Ross on this he'd say he was talking about the government's alleged involvement with the phenomenon and the cover up. He was implying (to me) that agreements were made and also that the cover up was worse than killing people, which is a pretty high bar (possible inference: government knows about and doesn't prevent negative abduction experiences).
This, to me, goes far beyond Elizondo's "somber" remark where he seemed to be implying something about the nature of reality or perhaps humanities true origin or history.
Again, if pressed, I would expect Ross to walk that extreme position back, using some context to frame it in a way that makes it less sensational so it doesn't sound so wild (unhinged?).
I am cautious, as always, to lend any weight without other sources. He's definitely been at the center of a lot of this unfolding story, and I expect that to continue, but I think he's very happy to pump up things like this to get more eyes on his work (that's human nature).