Knight Rider, The A -Team and Harry Potter Fantastic Beasts could be coming to Lego Dimensions according to some community investigations on various forums.

We had a look at the LEGO Ideas projects for inspiration:
Lego A Team – https://ideas.lego.com/projects/49825
Lego Knight Rider – https://ideas.lego.com/projects/47379
Lego Sonic – https://ideas.lego.com/projects/16256
Lego Minecraft – https://ideas.lego.com/projects/113251

We also have a close look at the Lego codes referenced in this blog post:
http://minifigpriceguide.com/wordpress/some-other-set-rumors-75098-75827-and-others-etc/