@ieugen Read the blog post that XCP-NG posted today on this very topic, but even if the decided to stick with CentOS 8 Stream for the future base platform, they have selective control over which packages/updates would get released for XCP-NG.
I've already switched my CentOS 8.x installs to CentOS 8 Stream. Fedora is too buggy and too far upstream of RedHat for my personal taste. CentOS 8 Steam is supposed to be positioned between Fedora and RedHat, so they might just hit the sweet spot.
Of course, if XCP-NG switched to Ubuntu LTS releases as the base going forward, I wouldn't cry about that either, so I anticipate this announcement from RedHat won't really affect XCP-NG and we'll look back on this and realize it was not a big deal.