Hello,
I had this same misconception. I mistook a custom for a rule, and then was educated that the CO's have discretion in this matter.
On the topic of website and forum improvements, I know that when we comment on a thread, then that thread will appear under 'Show new replies to your posts.' Is there a way to deselect the 'following' of such a thread? I once accidentally commented on another ship's discussion thread, and that thread has forever appeared in 'Show new replies to your posts' and I would be grateful for the opportunity to somehow deselect it from being followed.
Cheers!