I guess more - not just from a clinching perspective, but are they like the VA 600s, NC 4-digits, NY reference routes, or the QC 5-digits? How "official" are they? Any insight?
You're talking about the three-digit Yukon routes, right?
I can't compare to the other kinds of routes you listed, since I've never heard of the Quebec 5-digit routes, and don't know how the other three differ. All I can say is that since Yukon has no equivalents to county governments, and only a handful of municipal governments covering only a tiny fraction of the territory's land area, any rural road that's not private or in a national park would be maintained (if at all) by the territory rather than some other government. That would make them kind of like the VA and NC secondary routes, except for being unsigned.