From pylint's beginning to pylint 2.14.0 included, we had a changelog that contained all nontrivial changes to Pylint, including changes that were not user facing, i.e. change that might interest you only if you're a developer working on pylint or pylint plugins or an open-source historian.

From pylint 1.6.0 to 2.14.0, on top of the full changelog there was also a summary of (mostly user facing) changes.

Ticket numbers are almost can be internal to Logilab, or from bitbucket. In latest version it's also github issues.