Quickleaf
Legend
Something released under a CC-ShareAlike license would not be usable in the DM's Guild, because then the work would have to be released under the same license and the two are incompatible. It's basically the same problem as using Open Content in the DM's Guild.
Similarly, you wouldn't be able to use a non-commercial CC, because the DM's Guild is commercial, or a non-derivative CC because your work is derivative. So the only CC license that would apply is the basic CC-BY.
Also, that particular map is released under the GNU Free Documentation License, which is not the same thing as Creative Commons (though it's similar to CC-BY-SA).
Interesting. Do you know anything about that Zakhara map's author?
I just saw his username (or the username of the one who posted it to the wiki, but no contact info). And when I clicked the GNU Free Documentation License link it took me to a CC-BY-SA page!