You might also want to look at Passkeys support?
Passkeys is pushed by the FIDO Alliance, of which Microsoft is one member. It makes sense for all Microsoft-owned platforms to move in the direction of using Passkeys. Given the industry weight behind it, I would assume that FOSS will need to support this.
I don’t think that the intention is malevolent but I think the end result could be bad. For this technology to be viable from the perspective of privacy, there will need to be hosting options that are independent of Big Tech or, in the extreme, self-hosting options.
All that aside though, if you don’t trust Microsoft (and who does?) then you should be migrating off GitHub. Simples. 