I think that also comes close to why this sort of thing is so rare in America and unrelatable for many Americans. Thanks to America being more or less the pop culture hub of the world there kind of *aren't* bands massively popular in America that are virtually unknown elsewhere.
Yeah you can name guys like Garth Brooks as Mod Lang did, popular in the US but not really anywhere else. but even he is still internationally known to a greater extent than the Tragically Hip was simply by virtue of being popular in America. A band can't get big enough to be "just" a national symbol in America, because once an American band gets big enough they're a worldwide phenomenon, not simply an American one.
And even beyond that, America is so different from one region to another that it's pretty dang rare that one act would unite the whole country anyway, I could see people in the south weeping for Garth Brooks's death, but folks in the pacific northwest probably aren't going to give a single shit. A guy like Tom Petty probably comes the closest (and he's deservedly been getting tons of accolades since his passing), but he was also popular internationally. once you're able to have such wide appeal that all of the US likes you, it will be impossible for the rest of the world to ignore. But that's not the case for Canada (and that goes for other countries smaller than the US too. Australia probably has a bunch of acts in a similar position to The Tragically Hip I'd bet, so would many of the biggest bands from various non-UK European countries).