I have this same problem, the account I used seems to have been disabled.
What is weird though is that the connection between the disabled(?) account and my GitHub-repository is still up and running, as I just updated the code to support the latest version of WoW retail. Lo and behold, the add-on got updated and it's possible to download the latest version through CurseForge.
So to summarize, the account with projects and connections seems to be alive and well, but there is no way that I'm able to access it. Would be nice to get access back to it.
If I won't be able to access that account, would it be possible to request a transfer of the project somehow?