They added 4 lines of no real consequence in their version:
https://github.com/WinampDesktop/winamp/issues/265#issuecomm...
> It's technically a GPL violation, but not a massive one
Keep going through that thread, there's other stuff added too.
No company is ever going to release a closed source retired product again.
If they're not infringing on free software licenses I don't see why this would impact that decision.
Related: Winamp removed "No forking" restriction from license (36 points, 1 day ago, 11 comments) https://news.ycombinator.com/item?id=41650355
Who are we kidding, they're all doing it. I'd be willing to bet 80% at least of proprietary distributed binaries contain FOSS software and are in violation of licenses.