Well, if someone owns a particular bit of content, then they can make it available to different people under different terms. This is not particularly unusual; for instance a lot of Ruby stuff is (or at least was) released under the "License of Ruby", which allows people to use it under the terms of either of two different license structures. (One of which, confusingly, is called the "Ruby License".)
TV Tropes claiming to own the content may be dubious, but if you accept that interpretation, it's fairly reasonable for them to be able to release the content under both commercial and noncommercial licenses.
-Morgan.
TV Tropes claiming to own the content may be dubious, but if you accept that interpretation, it's fairly reasonable for them to be able to release the content under both commercial and noncommercial licenses.
-Morgan.