The issue comes up from the microsoft acquiring github.

Currently, there are only one way to login to MDN web docs, that is github. So if anyone wants to contribute to MDN, they must accept the privacy policy of mozilla as well as github. People are comfortable with mozilla, but after microsoft acquisition, many person do not comfortable to share their data with github. So that will be a berrier for them to contribute in MDN.
Moreover, a good issue comes from the IRC that, if anyone wants to delete his github account, the only one thing that will prevent him is MDN web docs. because if he delete his github account, he can no longer contribute to MDN web docs.

I understand that adding another authentication method maybe complicated. But we should consider it in the near future. Maybe Firefox account is well suited with our needs?