I do agree that they need some free sampler version for PS+ with 4-8 characters to revitalize the game.
The game will be revitalized by exposing the game to people on PS+?
You're saying they should release a glorified demo. I doubt that would bump the game by even 10,000 sales (or even more than 1,000).
If they really wanted to reignite interest by targeting the casual audience would be to better explain what the new product (season 2) actually is to potential consumers.
They've fucked up royaly though as ultra David mentioned at psx by locking the moniker as "Street Fighter V".