My understanding was that DS9 (and I thought most, if not all, of Voyager) was made on film like TNG, then edited on videotape with effects added. Creating a HD version for them would be the same process as remastering TNG. As far as I know, the reason this hasn't happened is the cost involved.
Edited to add: https://treknews.net/2017/02/02/why-ds9-voyager-not-on-blu-ray-hd/
He's trying to normalise the idea of the US taking control of Canada. It's utterly insane, but if he repeats it enough plenty of people will just switch off or subconscious accept that Canada "should" be part of the US.