It turns out Ubuntu 22.04 LTS is planning to use the Linux 5.15 kernel as its default kernel. It makes sense in that Linux 5.15 is also a long-term support kernel, but unfortunate in that Ubuntu LTS releases haven’t always used LTS kernel versions and v5.15 will be a half-year old already by the time the “Jammy Jellyfish” ships in April. This is a choice particularly unfortunate for those with recent hardware but at least there is the Ubuntu Mainline Kernel PPA and other non-default options available…
Source: Phoronix – Ubuntu 22.04 LTS Planning To Stick With Linux 5.15 By Default