Get subscribe-mails of closed topics

[SimonHof]

It would be great to get a subscribe-mail when something is posted in a closed topic.
I'd like to use this setup for a write-protected topic, but it's also useful if a mod closes a topic and explaines his action in a reply afterwards.

A ticket was created as mentioned by Stephen Edgar in ​https://bbpress.org/forums/topic/use-topic-as-mailing-list/#post-155395

[thebrandonallen]

Moving this to Under Consideration to help clear out the Awaiting Review milestone.

This seems like a reasonable request to me. At the very least we could funnel the "is published" checks into a short-circuit filter, so developers can decide how to handle this scenario via plugin.

[johnjamesjacoby]

Makes total sense to me, and easily achieved now.

[johnjamesjacoby]

In 6616:

Subscriptions: Include closed status in subscription triggers.

This change allows activity in closed topics to trigger subscription emails. It also fully implements bbp_get_subscribers() completing the deprecation of topic/forum specific handlers.

Fixes #2729.