It's official! Ubuntu 21.04 is now powered by Linux kernel 5.10 LTS as the packages landed earlier today in the main archives of the upcoming release.
Until today, Ubuntu 21.04 was using the Linux 5.8 kernel used in Ubuntu 20.10 (Groovy Gorilla) and more recently in Ubuntu 20.04.2 LTS (Focal Fossa). After several weeks of testing, it would appear that the Ubuntu Kernel Team decided to give a green light to the Linux kernel 5.10 LTS packages, which were kept in the proposed repositories for proper testing. This is good news for Ubuntu fans, as it looks like Linux kernel 5.10 LTS will be supported until December 2022. And Wayland (previously) is enabled by default.