Money does not have a smell of a fart.
I have never been in Dubai, but as much as i have heard the Dubai and UAE in general are trying to move from an oil producing country to country which gets their income from a multitude of sources including tourism. While being a muslim country de-jure with all its drawbacks and side-(d)effects it tries hard to be country where everybody is welcomed as long as the visitors are not trying to intentionally undermine all the important details of the muslim culture. Everything and everybody is available as long as you have money, connections and accept some limitations.
So why not have a mormon temple if it brings extra tourists who spend money in UAE instead of another country. I guess it is pretty slim chance that well behaving mormons are consuming lot of alcohol and roast a pig at public places and having a LGBT parade at first opportunity.
Somebody with good data mining skill can probably find the number of travellers between SLC and DXB/AUH and determine whether the temple is meant mainly for expats or also for Utah and US based tourists.