When will the new wiki show up?
The tag wiki shows up now.
An excerpt is required for the tag wiki to be shown. The edit help does say:
Under normal circumstances, an empty excerpt cannot be submitted, but there is an edge case mentioned in the answer to: Omitting Excerpt Section of Tag Wiki Blanks Out Entire Tag Wiki
Your suggested excerpt was rejected, but the full wiki was accepted, so you fell into the edge condition mentioned there.
(I just copied one sentence from your tag wiki to the excerpt, feel free to improve on it.)