GPL is still a commercial compatible license, something the team behind Duckstation, apparently, don’t like.
…also, this is something you’re not supposed to do. You can “change the license” to your own work, but the work done so far (by contributors) was GPL… so, a bit messy, I guess.
The repo owner claims to have permission from contributors to relicense (and rewrote some other parts where they couldn’t get permission?): https://github.com/stenzek/duckstation/pull/3295#issuecomment-2348988362
I don’t really understand the rest of that comment though…
It reads like the usual thing you see with retro gaming types: someone, who probably has all the right in the world to do so, makes their version of something without the original person’s name on it, and original dude has a little fit about how they’re being denied their due credit or whatever.
Like, not the first time this has happened, and certainly won’t be the last time it happens.
Though I doubt he really has the ability to change license on a whim like that, but it also doesn’t matter, because it’s not like that’s retroactive. Just fork it before guy had a fit, and forget he exists, and move on.
You’re not supposed to use Creative Commons licenses for software, though.