It seems like the model has been leaked (not by Meta) and is being distributed via a torrent. Someone has created a PR to the repo as a joke, suggesting that instead of filling out a form and waiting to be granted access (which is the official way to get access to the model), that you could just download it via the torrent.
Theyre giving it to universities for free. Someone got access and then made PR with a link to the torrent
it's a pull request from ChristopherKing42. He is unlikely to be associated with Meta.
Sending via HTTP will incur bandwidth costs. Torrents massively reduce this cost in the long run by making it P2P.
Edit: maybe in this case it's a leak though
Torrent can also be really, really fast with enough seeders, even giving CDNs a run for their money.