I thought the question in the title was easy: of course the wishlist question goes against the FAQ. It's not really meta, it's actually not about the site's operation at all. However, upon re-reading the FAQ closely I don't see it that clearly anymore.
The FAQ (which seems to be still the short beta FAQ) says two things relevant here:
Any question relevant to our community is welcome here
Avoid any questions that have nothing to do with mathematica.stackexchange.com
Clearly, the wishlist is relevant to the community; the number of answers illustrates this. Given that the question's topic, Mathematica, is shared with the main site, the second condition is met too.
But we have this 'Not constructive' reason for closing, haven't we? NC Includes the following:
We expect answers to be supported by facts, references, or specific expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, see the FAQ for guidance.
A clear match for the wishlist question, I'd say. One problem, though: NC is not mentioned in the FAQ. It is in Stackoverflow's FAQ, but not here. I think our FAQ should include it as well, but as long as it isn't the wishlist question is IMO 'legal'.
This question is perhaps not so much about the wishlist question as it is about the FAQ. Does it need updating in this respect?