I think it'd be unnecessary, because most of us watch the main com anyway, but also I'd be worried about the possibility of scaring off potential fillers. If there's a fill that's inspired by a prompt, even when it doesn't really fill it, it could still lessen the chance of a proper fill.

This is a discussion that goes over a lot on the Sherlock meme. About what scares people off of filling prompts, and "claims", a "first fill", and "an RTYI" are the usual answers.