I think we should blacklist it.
I think the tag as currently applied is not adding useful (or correct) information to any question (or when correctly applied seems to be a red flag for off-topic, better-on-StackOverflow questions). Further, I cannot think of a good way in which it could be applied in a game-development-specific fashion.
I went through the list of approximately 20 or so questions that had the tag. Most were already closed, usually because they were "debug my problem" questions or generic programming questions dealing with compile error messages. Many were incorrectly tagged (for example, actually being about link problems or runtime behavior issues) anyway.
"Compilation" can refer to a lot of things. It can refer to the compilation of C++ programs, or programs in other language. It can refer to the compilation of shaders, or the compilation of data. In all cases the word is the same, referring to the general process of producing something from some other set of things, but the actual details of the underlying process are not. Thus, it is unlikely that there are any experts on the general process of compilation that are not experts on compiler theory (which is a topic of SO, not here). The wide variety of meanings of "compilation" eliminates the categorization (and searchability) utility of the tag entirely.
After I culled out the questions that were off-topic, or used the tag totally incorrectly, we have a grand total of two questions:
Now, I don't think these are great questions in general, but I also don't think the
compilation tag even fits them. The first question is not asking anything about the compilation process, it's just asking if you need a specific version of tool to do a specific thing with a library.
compilation doesn't help much here, because the version incompabilities extend into domains beyond just the compiler.
The second question isn't asking about the compilation process either, it's just asking if one has to compile the engine from source to use it (a yes-or-no question, incidentally). An expert in compiler theory is not going to have the answer to this question, necessarily (although an expert in Unreal would).
Thus, I don't think this tag is useful to the site.