Trigger a notification when a thread is moved into a theme or plugin forum

[zoonini]

If a moderator moves a thread from a general forum like Fixing WordPress into a plugin or theme forum, no new-thread notification email is sent.

As it was explained to me, this is the expected behaviour for content that's already been published in the forum.

However, as theme developer @ilovewpcom pointed out in ticket #5535, this can pose a big problem for folks who monitor theme and plugin forums by email, as we may never know that a user's question has been posted in the forum.

This also affects the systems that some theme and plugin support folks/devs have set up, where the same email notifications mentioned here automatically create cards for each thread in Trello or another project-management tool. When there's no email, the card is never created, and the user's question may go unanswered.

Spot-checking the theme and plugin forums one covers manually is certainly a possibility, but it does pose a challenge when one monitors multiple themes and/or plugins, where manual checking can become quite cumbersome and time-consuming. It would certainly be more ideal if the notification system could be tweaked instead.