You know what.. You can sue right??
aint this how Ryan Leslie had to pay that dude for promising a large sum for finding his laptop?
That was a contract - Leslie promised to pay whomever found his laptop. The person accepted and found it, fulfilling the contract so Leslie had to pay.
Beans case is different -Kanye may have promised him, but beans doesn't have to do anything for it (there is no consideration), so it would be more a gift as opposed to a contract. Beans would have no case to force Kanye to pay.
It's like telling your coworker next rounds is on you but you dip home. They cant sue you for breaking your promise.