It was in fact leaked.

https://news.ycombinator.com/item?id=29379346

There's another open-source media player that will let you load up WinAmp skins. But heck if I can remember what it was, or find it. It looks nothing like WinAmp without the skins though...

While I was searching, I did find this though. http://qmmp.ylsoftware.com/ QMMP seems to be a QT-based player that looks like WinAmp.

And I can't find a WinAmp clone that works on MacOS, either. I'm dying for one since I have to use a Mac for work, and that's when I do most of my listening. I love having the little tiny player up in the corner. Visible, accessible, but out of the way because it's so small and you can shade the window!

EDIT: I found it! Audacious supports WinAmp skins also!

I'd say it has effectively been succeeded by Audacious:

https://audacious-media-player.org/

... which is under active development:

https://audacious-media-player.org/news/53-audacious-4-2-rel...