Sports books say no way they will block bets on Raiders games, they've been booking local UNLV games for 15 years now, no problem. But book operators don't have the final say in this, the State Gaming Commission does.
Betting apps for mobile use have been available for tourists for some years now, folks have been using them in their seats at UNLV games. And NBA and NHL preseason games. Even the NBA summer league play in Las Vegas.
Yes, Raiders won't enjoy the usual built-in home advantage, but will be offset a bit by the fact the Raiders used to that anyway (even when looked at as % home wins vs overall win %, they've been pretty poor) and the more undisciplined visiting teams will have a few players who are not 100% due to Las Vegas partying the night before.
There are plenty of projections of season ticket sales to locals, and those larger projections of attendance, and by-revenue generated to the city, etc - can't put much stock in any of this as they are all based on arguable assumptions and the unique situation here, of an NFL team being primarily a large entertainment show, makes these projections both more difficult and arguably less meaningful.
But no question is it a bit of a roll of the dice into the unknown!
If Las Vegas keeps growing and thriving, I don't think it will be much of a problem to improve Raiders attendance and revenue over the long run...