We've lost a lot with the deletion of this repo. Not the code - that's already out in the ether - but the absurdist comedy of the issues, pull requests, and commit history of trying to piecemeal delete third party non-FOSS software.
The other thing we lost is that future companies will think again before making their code public. It's already such an incredibly rare thing in the wild, but now companies and their lawyers will see that Winamp was exposed to potentially lawsuitable behavior that wouldn't have come to light had they never opened the code.