This is perfectly normal Ubuntu stuff. You aren’t having the 6.5 kernel replaced by this. It is a security update from Ubuntu to the existing 5.15 kernel you already have installed.
In *buntu installs, one can have multiple kernel ‘tracks’ installed.
For 22.04 LTS, the original kernel was 5.15.0. The HWE updates pull in newer kernel version on LTS releases, but do not replace the 5.15. Newer (non-server) Ubuntu ISO images don’t include the original 5.15 kernel track, but only the HWE kernels (currently 6.5). Older installs will have both the original 5.15, plus whatever the current HWE kernel versions are.
I think neon includes the original kernel as a fallback, since kernel updates have been known to sometimes break hardware support here and there, in Linux
You can remove the meta-package linux-generic, linux-image-generic and any 5.15 kernel and header packages if desired.
Ah yes… Makes sense now. I do have a couple of Kernels I can boot to in GRUB. I actually booted to an older Kernel last month because an update broke X.