Their release model changed with MySQL 8 -- they do rolling point releases every quarter with new features sprinkled in as they're ready. Quite a few new major features have been released that way, including INSTANT alters, parallel index builds, CLONE plugin, major changes to how UNDO logs are sized... it's more like Windows 10's release model.
Very recently they've mentioned they'll be changing this again to have separate LTS releases, which is a positive change stability-wise.