Linux Mint will be based only on Ubuntu LTS

It works really well. Actually lets us focus on getting everything done right instead of rushing to get new releases out every six months.

I agree. As long as major applications are backported then users shouldn't really notice much difference. If some users want bleeding edge, they're free to use Linux Mint Debian Edition which is semi-rolling. In the meantime, this change should free up developers to work on polishing Cinnamon and the many custom Mint tools.

Ubuntu has been keeping Firefox and Chromium up to date in releases for some time now, and that's a big help.

Back when I was running Debian, I'd use upstream .debs to keep OpenShot up to date (and it's more stable now than ever, I'm happy to report).

I think Canonical did a good thing by pushing upstream browser code instead of backporting security fixes to an older version.

If you do want/need a more stable browser, there are always the ESR releases that Debian is using.

I imagine LibreOffice being a bit of a "pain point," for some.

Clem sounds like he is rationalising Mint development after a period of rapid expansion. Cinnamon in particular must have taken a lot of time and energy. This looks like a good move. Generally there are few packages that need frequent upgrades and user experience is improved a lot by focus on the desktop responsiveness and feature set.