If their last major release was in 2021, they would have been too early for basing off the 22.04 LTS release of Ubuntu. Zorin 17 now appears to be based on 22.04 according to the /dists/jammy folder on the .iso image. The next Ubuntu LTS release is just a few months away, seems like rather bad timing for users. Even though Zorin 17 based on 22.04 will have standard support for 3 more years, it will put a bit more pressure on users to upgrade quickly if Zorin follows this schedule.
Edit: link with system information https://zorin.com/os/details/