In the requirements for the "Atlassian Verified" program it states that:
Use an issue tracker like JIRA to resolve and track customer-reported bugs and feature requests, for all paid-via-Atlassian add-ons. You don't need to use an Atlassian product to track your issues, but some kind of tracker to keep on top of customer-reported bugs and improvement requests.
Now, this doesn't say that the bugtracker needs to be public - just that we internally need to use a bugtracker.
On the other hand, in the vendor profile there is a field "Issue tracker" with the comment:
A location where users can file issues, bugs, and raise new features for your add-on. This is required for the Atlassian Verified program.
So... is it OK if I post a link to the forum that we maintain as the primary customer interaction channel? Our internal bugtracker is TFS which doesn't lend itself well to a helpdesk role. But in our forum we always reply quickly and use that to keep the users updated. It's what we've used so far for this purpose and it's working well for us (we even get praise from the users regularly about our quick responses).