Currently we have the possibility of linking the account to GitHub and it doesn't seem to be sufficient, so to be honest I don't really see how that will be much different - although I agree that this probably should be a sufficient proof of ownership.
I wanted to suggest an alternative in case it would be simpler to implement.
Well, looks like "sync with github" is also enough since it needs your github account authenticated. It just needs to be a required step.
Currently we have the possibility of linking the account to GitHub and it doesn't seem to be sufficient, so to be honest I don't really see how that will be much different - although I agree that this probably should be a sufficient proof of ownership.
I wanted to suggest an alternative in case it would be simpler to implement.