I think it wouldn't be enforceable in a consumer service (at least in my jurisdiction, see a German court ruling against WhatsApp banning a user for using a thi

I think it wouldn't be enforceable in a consumer service (at least in my jurisdiction, see a German court ruling against WhatsApp banning a user for using a third-party client by claiming doing so violated their ToS). But given that implicitly or explicitly GitHub users act more like users of a commercial service (remember: commercial doesn't mean paid or b2b), things might be different given that consumer protections don't necessarily apply. Personally I'd love to see the same "you can't hide surprises in your ToS to obtain 'consent'" yardstick be applied here though, commercial service or not.