I just submitted a few suggested edits to tag wikis on Computer Science, (137–146). All of them were newly created excerpts or wikis. They have been rejected silently: there is no indication of who did the rejection, not even Community. None of the users in the CS chat saw the edits, though one reports “I did see something in my status bar, but they had disappeared before I could look at them”.
To see if this was a site-specific bug, I tried a suggested edit on Stack Overflow to an existing wiki. It was “Pending” for a few seconds, then after reloading the page, it became “Rejected”, again with no explanation.
It looks like suggested edits to tag wikis are silently lost.