I’m running Mate 16.10 on my Raspberry Pi 2 and 3. There are no longer any updates available so Mate recommends upgrading to 17.04 which is not available here. Since you’ve dropped support for the 16.x releases, we no longer get security updates. Is there a targeted date for at least a 17.04 release?
Where did you get MATE 16.10. There is just 16.04 which is LTS.
It was part of the upgrade process many of us have used and it worked fine. I installed 16.04 from the image and when 16.10 came along, it was offered as an upgrade but officially unsupported. This upgrade process worked fine. However, there are no longer any updates available for 16.10. There’s a note on another forum that someone does have 17.10 running but my upgrade attempts have failed…