I had received a message regarding a fraud email / promotion that bitcasino.io is sending, I will make followup on these before make my self judgement if they become a scammers.
You should provide more information about the email you are getting from them so we can understand the contents. Actually those email may not be a scam one but an enticement for you to play casino on they site. But casino. io look so real to be a scammer at this early stage.
You do know that bitcasino.io has other sites under the same management.
Vegascasino.io , sportsbet.io and this one are all operating out of the same office overseas and has the same head manager for all these casinos.
All their promotional emails look the same too.
So it is hard to tell where they are coming from sometimes if you aren't looking at the subject line in the email.