Tag wikis on Meta don't show the edit button to suggest edits. Empty tag wikis have a “Propose Tag Wiki” button, but it doesn't do anything. So only 20k users and mods can edit tag wikis on Meta. Is this by design? If so, then the page for empty tag wikis is misleading.
Citing Jeff's answer from meta.math.sx:
I wouldn't mess with meta tag wikis -- we plan to export all the common, standard meta tag wikis from meta.so.
(There might be an exception for topic specific, special per-site meta tags but these are quite rare in my experience.)
I definitely encourage anyone interested to assist in editing the main site tag wikis, however, particularly the page 1 tags.. please!