It has already been discussed earlier that the mention of cryptocurrency immediately creates negative associations with criminal activity in many people who are completely unfamiliar with it. So it all also depends on how a specific employer or even a judge, as you mentioned, treats cryptocurrency. And since the attitude of these people can be negative and they immediately associate such an employee with offenses and participation in illegal payments, then the decision to dismiss becomes quite natural.
And also the decision to reinstate in the position by a court decision, too.
It is a completely normal process when cryptocurrencies were previously presented on TV as something incomprehensible to people who are accustomed to traditional financial assets, and they also tried to denigrate them by saying that they are used for something bad. But we must not forget that the dollar is also used for something bad, but no one even talks about banning the dollar. If a fired employee had bet in dollars, he would also probably have been fired because gambling is prohibited in the workplace. In short, you can play, the main thing is that the employee was not noticed playing, lol.