For me it looks like listmast@lists.perl.org is still official the feedback link today.

You find it on lists.cpan.org in the menu on the left side, the fifthmost link from the top labelled 'Feedback'.

It might well be that it has not been working since several years, but it is certainly still there, advertised on the main page for 'Feedback'.

Googling the address I see that the problem is out there since at least 2007, so there is some abandonment around in the perl world.