How or why is that? Why would it be easy to cash in or sale 4 billion dollar worth of crypto in Russia? Russia probably doesn't extradite a person to Americans (not sure about non citizens) but there are plenty of sharks who would want to get their hands on these coins if that came to public anyway.
They have not extradited Snowden. If it is politically favorable they would grant residency. There are other few other countries who who do the same, but only one or two like Russia could withstand U.S. pressure if they harbor such a high profile figure.
Of course Putin will take all the money anyway, so what is the point ? Getting the mob for support never ends well.
Also to note one of them is a dual Russian citizen so it more complex than the hypothetical
