Should YC change “GitHub URL” field/lable in founder's profile?

No.

Use LinkedIn for pro, github for tech.

It works for other sources if needed and shows where you deviate from the norm.

Not a problem IMO

Was using BitBucket, needed private repository. Then switched to GitLab, because of CI/CD. Maybe same is happening with other developers.

Yes change it to ‘Subversion URL’

:), remembered times using VSS, u could lock a file.