This may be a rhetorical question, since I've found no evidence of any such discussion so far, but I'm going to ask it anyway.
I was more than a little surprised that there wasn't a site for such a topic. Something for actors in theatre, TV, and movies (as well as performing arts schools) to address questions around their craft.
I am new to Area 51 and have never proposed a site before. I went through the initial process, but I have no URL for an "audience" to give, which is one of the three initial questions for a proposal.
I am happy to be a catalyst, receiving input from people and acting on (no pun intended) information about creating such a site if there is enough interest.
I imagine that at a minimum, this question would need five upvotes (assuming an upvote means you would follow such a site and, hopefully, help build it), as well as some concrete ideas about where an audience could be found. (As well as some input in comments.)
Assuming it gets even that, I can propose a new site. If it doesn't get that, then I'll take it that there is no interest—but at least the subject will be discoverable for anybody who thinks about it.
Note that I am simply asking for interest in this idea; I am not asking for anybody else to do anything on my behalf. I am quite happy to put in any required work to go through the process.