People don't truly check whitepaper, except a few, so I've heard a few players, arguing on Twitter about this. One of them argued that no one actually checks whitepapers and that it was a sudden move to pull, even if the SPS requirement was there in the white paper.
You have to have an amount of staked SPS before you can join a certain league?
No, you need a certain SPS requirement in whatever league you are to compete for maximum rewards in that league. It's a new change that's buzzing on splinterlands.