Hi and welcome to the forum. Those upgrades won't install because Zorin 16 is based on Ubuntu 20.04 (Focal Fossa), Jammy (Jellyfish) is the project name for Ubuntu 22.04 which is what Zorin 17 will be based on. If you had managed to install such upgrades you might break your system. So the reason nothing got upgraded was to prevent you from baulking your system.