It is even possible that new exchange developers who plan to develop this potential will much prefer the UAE as their place because the absence of tax is quite profitable. Although in terms of regulations we never know how the taxation there is so far for companies that will be built there.
I'm not really sure for the exchange's tax but there's no personal tax on crypto for the ones who live in UAE. There's no tax on any capital gains from crypto investment or from trading, and that thing is really exciting for most crypto users. I don't know personally but I believe there could be some taxation for companies.
I don't know what the law will be in the future, but here in my country, we don't have any crypto tax unless for the recently launched licensing fees in cryptocurrency exchange and the fee was huge enough to discourage any potential exchange developers and operators but aside from that one, what I have also noticed is that most of the countries that don't have crypto tax or any regulations that could subject cryptocurrency income tax is for the fact that their lack the capacity to do so and for that reason they just decide to play a def war to it and just walk along with what is available.