From the above article entry:
Everyone except US citizens can participate in Edgeless staking. Due to uncertainty in the US in regard to the regulation of tokens, this feature is not available to US citizens for now.
Frankly I don't know if this will even deter the US government from poking its nose into Edgeless' gambling platform. The US has been very busy lately intervening in other states' business. I hope they won't go too far.