Hi @samuel15, see this thread for timeline for the Ubuntu 20.04 upgrade for Xavier devices:
https://forums.developer.nvidia.com/t/jetson-software-roadmap-for-2h-2021-and-2022/177723
JetPack 5.0 will be the next major release, and will include an upgrade to LTS Kernel 5.10 and Ubuntu 20.04. Other noteworthy changes include support for UEFI (replacing CBoot), support for OP-TEE (replacing Trusty as the trusted execution environment), and an upgraded compute stack including CUDA 11. The Developer Preview of JetPack 5.0 is planned for Q1-2022 and the production release is planned for 2H-2022.