So just bad timing, or did they choose the wrong kernel?

Just bad timing, or does Debian hold onto old kernels longer then everyone else.

Still, should be easy enough to update a kernel in any Debian based distro.

It was not that long ago I was fine with the 4.19 kernel.

“but it comes with a newer kernel, namely Linux 5.18.2, from the Debian Backports (Testing) repositories.“ ??

My guess is its just bad timing to launch a major version of your Debian based distribution. 5.19.1 is in Experimental so it’ll probably hit Sid soon and will probably hit backports as 5.19 will be stable and not EOL through the next couple months.

Pkgs dot org (not a definitive source) says that Fedora 36 is on 5.18.18. Which is obviously also 5.18.x. So the mythical Fedora-based distribution launching today would have the same issues.

My guess is 6.0 will be around the corner.

They seem to use the newest supported kernel by Debian stable from the backports repository. Nothing wrong with it per se.
I do not even use a back ported kernel on my Debian system as their is no need for one.