I'm fairly sure this will just create another useless echo chamber of likeminded people who don't represent the masses of community.
There are two big reasons that lead to this:
1. They want persons that are so involved in WoW that they create videos, guides, stream the game etc. aka not representative of the majority of players who are not doing any of those things. So their mindset and wishes don't necessarily match.
2. This is just a guess, but I assume that applying/participating in the community council requires an active subscription, just like the Blizzard forums in general. A person who is currently subscribed to WoW certainly doesn't represent the masses of players that are currently unsubscribed for X, Y and Z reasons and the 95% of players that have "permanently" quit the game throughout the years.