And their point is that saying “copyright free” will probably be more immediately understandable to people who don’t know that and don’t want to read a small comment about copyright ‘intricacies’ (even if it’s not that intricate)
By saying copyright free, more people who need freely-licensed works like this are likely to use it instead of being warded off by “this does has a license, it’s copyrighted, but it’s actually free because of the license”
By saying copyright free, more people who need freely-licensed works like this are likely to use it instead of being warded off by “this does has a license, it’s copyrighted, but it’s actually free because of the license”
Colloquially, it’s the same thing.