Though I find it completely sketchy for them not to allow the withdrawal at least to go to pending while they hot wallet gets replenished . Normally when he tryed to withdraw his balance should've been removed and the withdrawal to be pending while they replenished the hot wallet .
Maybe Megadice are doing it on purpose ? Going on the probability that if a user won't be able to withdraw / his balance remaining intact on the account the said user might continue to play improving the odds of him losing the balance .
We can reassure you that we had it like this since day 1, even back when satoshislot was a separate site in 2015, i would say. There is no intention to do anything, just that we find it bad to lock user funds so that we wont be able to do anything with them. We may consider such functionality though, so that someone can decide to lock funds for withdrawals if he wish.