It's been said before, but I wonder if season 2 has an intentional 30th anniversary theme, because every single character was first seen in a different Street Fighter series. That would be one hell of a coincidence.
FF - Abigail
II - Akuma (better than the NPC alternatives of Ken's wife and Gorbachev)
Alpha - Zeku
III - Kolin
IV - Ed
V - Menat
Only the first Street Fighter is missing, and that's probably because not even Capcom thinks Retsu or Lee are worth including.
Speaking of themes, what would you like to see for future seasons?
2018 - 6 fan favorites (Sagat, Sakura, etc.)
2019 - 6 Final Fight characters to celebrate the 30th anniversary of Final Fight
2020 - 6 brand new characters representing new regions and fighting styles (Sub-Saharan Africa, Scandinavia, Indonesia, Australia, Polynesia, etc.)
This would bring the total roster count to 46 characters. I think we'd be lucky for DLC support to extend beyond that.