Granted, you've found the one (and only?) notable exception to the "no legitimate torrent use cases" rule that I can think of. :)
And this has a legacy roughly as long as BitTorrent itself. The fact that BT never established a footing in other use cases (even those where you would think it would be a great solution) is telling.
I had forgotten about this, this is an interesting exception.
Windows Update also allows the user to opt in to use a non-bittorrent protocol for peer-to-peer delivery of updates to other Windows users. But of course, it's not true Bittorrent.
That’s fair, I never got into torrenting for illegal purposes but even I had the feeling that we were acting as the thinnest veneer of legitimacy when torrenting distros, haha.