well... Ohlmann and Tilo Holighaus were showing off a bit on the Marina during December 2015 (It felt so nice to see some gliders there).
https://www.youtube.com/watch?v=zJ9OAxv8YJk
On another occasion I saw a (I believe it was) Stemme over the Marina/SkyDive Dubai during the last week of February 2016 (low ceilings and that machine was never loosing height... kept flying and flying)...
I believe that it is difficult to have them in Dubai as there are many constrains in the airspace...
I was dreaming that Fujeirah or DWC one day would open a GA/Glider club...