Queuing as Support Role Priority
When you choose Support for your first role, you should get it.
If a lack of players taking support is a problem enough that Riot has taken steps to correct it, like autofill protect; Then when a player CHOOSES support as their first role they should get it, ensuring there are more supports spread out throughout the queue. I shouldn't play multiple games as support to be suddenly thrown into mid, top, etc.. even with autofill protect on.
I just think that if I'm one of the small minority of players who actually WANTS to support, it only seems logical that I would get support in queue and not something with a much higher priority.