Considering the number of Perl6 related posts other than the lengthy "please rename the thing at last" threads either the people that care about that language already found some other place for their discussions or there's so few of them that it doesn't matter whether they post something here from time to time or not. Even I think it's more of the first.
So wait for what? Wait to see whether it's something that needs to be solved. If the Raku people need PerlMonks, they'll post here and if the number of posts is high enough, it makes sense to make an official policy. If they do not need PerlMonks, then whatever you write into the policy is irrelevant anyway.
1984 was supposed to be a warning,
not a manual!