From what I know the tax exemption there in Dubai is limited and also has some rules and exceptions. But looking at the news I see that the cryptocurrency company won't have any problem as the country Dubai is one of the easiest ways to put up a business. Their type business is pretty diverse and I think it will be a success as they will be offering the services first in that country. And the services are:
offering brokerage services and an insured, high-security cold storage service for bitcoin, ether, bitcoin cash, ethereum classic, ripple, and dash.
These are one of the things a cryptocurrency trader and user are looking for the only thing they have left to do is of course attract customers to use their services which I think is a hard task to do as of the moment.