How should this theme be licensed?

[clausmullie]

Should the license change from EUPL to CC0 on this? Or fine to leave it as is?

[jgroenen]

I heard CC(0) is not compatible with open source licenses (but I'm not an expert)?

[jgroenen]

No, never mind: https://wiki.creativecommons.org/wiki/CC0_FAQ#:~:text=Yes%2C%20CC0%20is%20suitable%20for,software%20licenses%2C%20including%20the%20GPL. Although they do mention considering an OSI recommended license (as does the Standard itself).