And if you are able to make winnings on large amount of bets, you are very likely to be banned by Stake.
I'm wondering why you are thinking it in this way! No reputable casino will ban your account if you win on your large bets. They will only ban you if you do it by cheating. Stake or any other casino will lock your account if you continuously win on big bets with suspicious activity. They will unlock your account if your winnings are legit.
I believe that no reputable casino site will not do anything like this. But if a user violates their mentioned rules and starts cheating then his account may be banned or temporarily locked. But if someone wins any big amount then his account will be locked I don't find any reason for this. It's just a funny quote . There is no justification for this