I'm just thinking that because I've never heard NVidia or anyone else ever say that DLSS or FSR will never work on such-and-such a game specifically because of what engine it's using. It's still up to the devs to implement it, but reconstruction is almost expected these days, and we've seen it used on pretty much every modern engine by now, haven't we?
Oh my bad, I actually agree that DLSS is engine agnostic. I was overly focused on "since it's applied after the image is rendered." That's the part I was actually replying to.