You mean that if you sent links to your Gitlab or Sourcehut profiles (or even your personal site) when asked for your Github profile, those recruiters would refuse to look at it?
I have no idea how it could happen in practice. It's quite believable that there is some recruiter out there that has this kind of problem. But I do think it's quite safe to assume most of the tiny minority that will click on the link will get the same information from either one.