You might have heard about the "drastic UI and UX changes for 114" and even more "we're planning a lot of things and we will release them when ready".
Well, that time has come and we now have a pretty clear direction and expectations for 114.
https://thunderbird.topicbox.com/groups ... pted-email
https://thunderbird.topicbox.com/groups ... ual-update
going by this the Next ESR will be 115 https://wiki.mozilla.org/Release_Management/Calendar