It means you don't have to pay the OC royalties for using their work in your projects. It doesn't mean you can use their work to train an AI model.
Viewing post in FilmCow Royalty Free Sound Effects Library comments
Extra? You never payed an upfront cost to begin with. It's not rocket science to take one look at the OC's page and see that they have purchasable items on their Itch page, which probably means, no, they would not be happy with you taking their kindly made Royalty Free work and feeding it into AI where it will then become apart of a larger ecosystem of AI trained sound effects all based on their hard work. There's also a license, if you've even read that!
you know, people who want to help society, are working on open source ai models. the whole heat+energy issue is present, but we can probably engineer past that eventually, but that aside, i would say that, like they said, not everyone is a suno, or other corporations who just wants to profit from renting out ai to displace artists.