That's will happens if bitcoin was strictly prohibited in the country it depends upon on the situation in bitcoin into a country.
Yeah, we all know that bitcoin is a decentralized technology coin and nobody could stop on the technology.
If a country has no law in cryptos also gambling has not prohibited or casino who used bitcoin for gambling.
Just like here our country we have freely used bitcoin here so we are not prohibited to do gambling.
The legality of bitcoin and gambling should be considered separately. While in some countries bitcoin transactions are illegal already, gambling is illegal in many countries. So considering the overlap between the two we can see that some countries will fall in the section where both bitcoin and gambling is legal.
Again bitcoin gives pseudo-anonymity and thus gamblers feel safer betting with crypto than fiat. Safer in the sense that they are less likely to be caught be others.
I agreed, every country has a different rules over the regulations an dlike in my coubtry there is still no strong regulations especially in online investments or casino's and still they are researching on it before to take some regulations along with it.