I have a firm belief that if Under the Weight were released in Shadowbringers, we'd have understood it far better and it would be hailed as one of the greats. It was, quite literally, before its time.
At launch we weren't prepared for lyrics to be telling us things or to really matter (and some of us might've not even recognized there even were any). So we didn't really think to actually dissect the high-speed rap for any sort of meaning until it was too late to be relevant and interesting. Under the Weight carries just as much meaning as something like Fiend, we just weren't really listening at the time.