Perhaps it is a good idea. I was looking for ways to convert nonclustered primary keys into primary keys and thereby I searched all question aboout clusterd indexes and noted that this one was missing the obvious tag and I added it.
Converting it to a CW gives the opportunity to link to further related questions like this, which shows, that instead of converting the primary key, I can just add a clustered index.
Technically there seem to be the possibility to change a question into a CW or a single answer. In this case it might be the question which to convert into a CW.