I would like to suggest that you add a role section in the forum where we are able to discuss certain role-specific topics that doesnt necessarily fit or include a single class. Like
-Healing
-Dps
-Tanking
Sections like these are vastly superior to class restricted section when you want to talk about generall things that only include a single role.
Section "Dungeons and raids" is similar to what you're talking about, but it's not that specific.
It could be added, maybe they just want all of pve in one section.