DS9 and Voyager will absolutely happen. While Blu-ray sales are nice, the money made off those are a drop in the bucket compared to future revenues. These will live on for decades through services like Hulu. Netflix, Amazon, etc. Crummy old DVD transfers just won't do.
Heck, if The Dick Van Dyke Show can get a Blu-ray release, surely DS9 and Voyager will too.
While I don't disagree with you, it's important to note how much more work is required to make DS9 and VOY worthy of any type of HD release.