That's also unlikely to be true. We saw both VP9 and AV1 come out within h.265's lifecycle (with at least 2 more years to go until the next spec is ready). Chances are there will be an AV2 coming out around the same time of h.266 release.

But either way, the whole industry has already backed an open and royalty-free codec. The release of h.266 (if that's what they're calling it) will be pointless because it's highly unlikely anyone will adopt it. They may as well release it as open source if they did the work anyway.