Disregarding everything else for a moment - A question about Flex Queues for Riot.

As far as rewards and rewards-related things are concerned are they any different?

For example if Solo Queue will be finally re-released as promised, will I have to play 5v5, 3v3 or both to unlock those "if you get Gold+ in both Solo and Flex Qs" rewards?

Is there going to be any difference between 3v3 and 5v5 rewards?