I like having these in. It makes the maps nicer, and allows for more specific statistics. In the case of the Thruway, it would have been nice to track stats on the mainline and the system (moot now that I've clinched all of it). I can see a case for most of the major toll roads in the US, as well (except for some cases, like the Indiana Toll Road and Massachusetts Turnpike, both of which are 1:1 the same with the portions of I-90 in those states).
Similarly, I can see a case for the routes in Western Australia, which would almost certainly be M routes if Western Australia converted to alphanumeric (as far as I can tell, it's more a reason of money than anything else). If Australia didn't have alphanumeric numbers, it would be more like New Zealand. It's not as if they had an equivalent of the interstate system that became the M routes. I'm more lukewarm on Tasmania, though - those are less a freeway system and more highways sections hat happen to have interchanges and no at-grades, with most of them being on A routes (and the remainder on national route 1, which would probably be an A route if alphanumerics had been thought of in the rest of Australia at the time; Tasmania converted a decade or two before everyone else and had federal pushback on route 1).
Likewise, were the unsigned interstates to go away, I'd desire a freeway system for Puerto Rico (I'd say Autopista, but many of them are Expresos for some reason, and at least on road marked "expreso" on Google Maps isn't a freeway). Maybe the freeway sections of the Seward and Glenn Highways in Alaska as well, though there's a case to be made that they might be like the sections in Tasmania (though they're longer and don't have the A route/M route distinction).