https://train-blockers.toolforge.org/ currently points to wmf.8 task T330215
The Previous 1.41.0-wmf.8 button should point to T330214: 1.41.0-wmf.8 deployment blockers but it instead points to T326177
That task got a Release Version instead of the tag MW-1.41-notes (1.41.0-wmf.8; 2023-05-08)
Aklapper set Release Version to 1.41.0-wmf.8.
I think that is the reason since the form configuration https://phabricator.wikimedia.org/transactions/editengine/maniphest.task/view/34/ has:
The release details are automatically generated from a template which uses the contents of the Release Date and Release Version fields to dynamically build all of the details for a given deployment cycle.
So I guess when the field got set on T326177 it ended up being considered part of the series of blocker. There might be some guard to add to the code.