As I said it will do favour for the country if that town having tourism as one of the primary source of income or else it is going to suck the money from their people itself and going to give bit to the government as tax and the remaining will goes to the casino owner.
Railways are expensive and really long term projects so it is not going to be considered when the country itself in the need of funds.
Perhaps, suppose the casino reopens in this pandemic, that can make the other businesses can reopen too. In that case, it can directly reopen the tourism sector because people from another city will come to that city, and they will play gambling together with other people. If that happens in this pandemic, then that can trigger the tourism sector too. And if both sectors can cooperate to attract more tourist to come to that city, sooner or later, the economy of that city will start to rise. People will have the way to open a new local business from the tourism sector while people can playing gambling in the casino.