#Community Suggestions
The issue with the idea of Community Suggestions as a board is that it has a similar problem to GD, though in a different way.
One of the big reasons GD became so popular is that people realized Rioters preferred to post there. I would assume Riot's being more careful to avoid that problem here, though, and
"The place where we suggest things for Riot to add into league."
Is very, very broad. This can include new champions, improvements to current champions, new lore, improvements to current lore, new art, improvements to current art, new systems, improvements to current systems, new maps, improvements to current maps, new modes, improvements to current modes, etc.
This is obviously significantly more specific than GD, but it's still something with the potential to drown out a lot of other Boards and make the content difficult to follow.