I wouldn't read that much into it. While a lot of Fedora people also work at Red Hat, Fedora really is a community project. It's quite possible that the community voted to use btrfs as the default file system, even though support is not planned for RHEL.
That said the RHEL people will be paying attention. If btrfs proves successful, I could totally see it going into RHEL 9.
Disclaimer: I work for Red Hat but not on Fedora. I'm just a happy Fedora community member for a little over 10 years now
