TLDR: Do you know of any uses for MassMessage, where it delivers identical content to the same page multiple times? E.g. content *similar to* a user-warning template, where everything might be the same except the timestamp.
I ask because we're trying to determine whether there would be any problems with a proposed solution (using "De-duplication") for the rare bug where MassMessage can post the same message to the same page multiple times due to JobQueue issues (see tech details in phab:T232379#5480718 https://phabricator.wikimedia.org/T232379#5480718). I.e. It would make it impossible to send *exactly the same message* to the *same page* regardless of timing. Would that cause a problem on any wiki that you know of? We think not, but want to be more certain. Thanks.