I'm not quite to 2500 rep on SU yet, so when I made a tag wiki for VBA, it said that it would have to be previewed and approved. That was quite a while back, and nothing's been done on it one way or the other. Who is responsible for previewing tag wikis on SU?
Either users with a reputation over 5000 or moderators can approve tag wikis.
You did create the tag wiki body but apparently left the excerpt blank.
Adding in the tag excerpt proper fills the landing page.