Hopefully this isn't bikeshedding, but the new text "The submission date for this assignment has been closed." (added in MDL-30481) doesn't quite make sense, as it's mixing together two statements "The submission date for this assignment has passed" and "This assignment is closed".

A better phrase: "The date for this assignment has passed, so it is closed to submissions".
Edit: even better: "This assignment is closed to submissions, as the submission deadline has passed"

I know the new assign mod is the way of the future, but it's likely my group will be using assignment for at least another year from now :-/