The majority of casinos have anticipated this and they know that the majority of gamblers are also investors and supporters of altcoins so they made sure that players have the option to choose what coins they want to deposit, It's very rare to see casinos that only accept casinos, they will lose players and profit in times like this and I doubt if players will continue to play on Crypto casinos with only Bitcoin as the only coin they accept.
The most popular altcoins, players choose are Tron, Doge XRP, and USDT you can see this on the majority of casinos.
The gambling sites was always friendly to the gamblers,because by that the gambler join to their site in the large number.The gamblers had lot of options to deposit to the gambling site,but if they get return in terms of bitcoin.This will help the gamblers to make some unique moves and help to earn more by just holding.Because bitcoin is the gold,any time it will give us more profit.It may be the reason for the OP had discussed about the potential for bitcoin to be used in the gambling site.Instead of holding at this specific time,the OP may use of the USDT,Doge and Tron for the gambling.This will affect the bitcoin holding gambler in the Binance exchange.