I know this isn't concrete yet, but I think due to the specific nature of the wording, it's more likely that we are getting 8 Playsets as opposed to 5.
If we do get 3 more Playsets, I think it'll definitely be Rebels, Ant-Man and either Tron or Frozen. Those makes too much sense for them to be anything else, IMO.
Whether or not we get 8 Playsets, I am very appreciative of all of the new content Disney has developed for 3.0. Just 5 new Playsets, 4 new Toy Box Game Discs, the addition of farming and 30-40 new figures is a lot to be excited about by itself, so the addition of another 3 Playsets on top of that would be amazing.
All of this recent news makes me more and more hyped to get my hands on 3.0 and all of the figures and Playsets they plan on releasing.
Can't wait for launch day!