I noticed that there is a new feature to filter the casino games by "providers", does it mean that Stake is going to add games from 3rd party providers?
If no, I do not think there should be such filter feature as all the games are original games from Stake.
So I guess Stake will add games from 3rd party providers in the future.
If it is true, I can say that it will be good addition as there will be more games to play and high likely there will be much more promotions.
Yep, they're coming. AFAIK they're currently in beta and you can get early access if you have a high enough VIP level.