If you think like that, do you think that all casinos with internal exchange will end in money laundering because players can deposit with a coin to play then decide to exchange it to other coins when the players are going to withdraw it for a reason? The idea of such conversion is not to make players use the casino as an exchange. The idea is to give players a benefit when it comes to withdrawal. It will be end in money laundering if people use it to deposit then withdraw the money straight away without playing. Any casinos wont allow such practices obviously because most casinos are against money laundering.
Surely it is kind of tactic to launder their money and everyone who wants to avoid the tax can get the benefits of it. Even hacked funds can be used to launder in that way so they can leave the site to take blame and will vanish with no trace of hack.
Lol gambling sites now are mature enough to evaluate if the Depositor is just using their platform for laundering purposes , they have tools to monitor those who was just depositing and then withdrawing .
Gambling sites has system to know who are those legit players and who are those not so if they tend to use the platform in launder activities for sure they will be freeze and has a chance of not getting their funds back as this is against the TOS of each sites.