Since we don't currently list all the same sites in the Map Details that GeoHack does, we shouldn't be limiting the options that users have for viewing maps.
Should the link say "map" - since it's really not one map but a link to the old GeoHack page which is a collection of available maps?
I was able to see the new link by visiting this wmflabs page: http://vem3.wmflabs.org/wiki/Main_Page#/map/0
and it took me to this geohack page that isn't functioning properly (JS disabled error): https://tools.wmflabs.org/geohack/geohack.php?language=en&pagename=Main%20Page¶ms=37.8041_N_-122.4098_E_scale:8000
Is the error from something that is being passed in the URL to Geohack?
I understand your point.
While I understand it does not perfectly fit in the Map category, I would prefer to keep it there so it appears on the first print of the sidebar, and since some users are particularly used to going to Geohack, I think it works well for them.
The metrics we collect should give us some conversion rate for the Geohack service, in comparison to other services. If we see that it's low, or even lower than other maps, we can move it out of the Map category.