I'd love to think so too, but I think our echo chamber is pretty tight.
I certainly think they're ready for mainstream usage (I have one Bazzite install myself), but I don't think there's significant awareness beyond the dedicated fan base.
There aren't really any actually useful metrics that I know of, but the only one of the 3 I've mentioned that broke into distrowatch's top 100 is Bazzite, and that's only in the last few months.
And for legal threats: I doubt any court in any country will give credence to that. Fedora is MIT licensed.