Hey ! Let’s see what Vitalik said… Quote "In the gitter discussion the attitude to this revelation was very laid back, Vitalik "yes, so the casper randao is NOT suitable for high value gambling use cases" and others “I don't see the problem, you could just not use RANDAO for these use cases”." So as we can see Vitalik himself don’t recommend using this option for these use cases, he did not say a word about these issues can’t be sold with other method. We are surein the near future, there will be information that Vitalik’s word either unknowingly or intends is distorted, and he didn’t mean that solving this problem would be some sort of a serious problem.

at the moment during the generation of random numbers, two types of data are mixed: a large amount of data transferred by the purchase of tickets from the user and data from a special amount of blocks after the draw is finished. The draw runs only after the tickets sale stops.  As for the user data, it must not be obligatory secret, it is just being mixed in by hashing. You can find more detailed information on this and other questions in our whitepaper that is available on our homepage.
http://kiboplatform.net/_alldata/files/kibowhitepaper.pdf