Regression tests for some bugs are not published in new MySQL releases. This was reported by the MariaDB project and Ronald. There are also delays in updating bzr after recent releases, but there have been delays in the past. Questions about what has changed have not been answered, so we are left to guess.
This matters to me. I spend a lot of time doing QA for MySQL and backporting fixes from new releases to the branch I support at work. It is much easier and safer to backport a few bug fixes than to upgrade a large number of servers. MySQL is much harder to make better when tests are missing and bzr is no longer updated. My teams at Google and Facebook have made MySQL a lot better. I wish we didn't have to deal with problems like this that slow us down. It might matter to you. While the corporate owners of MySQL have been productive, the community developers have also done a lot to make MySQL a lot better.
Maybe someone from Oracle will explain the changes to us. That would be a community-oriented thing to do. So, call us maybe?