You should ask Amazon, whose lawyers would need to authorize Sonos to activate the service. 

Presumably you mean that Alexa is available there via Echo devices; if so I am surprised it has taken so long to get there. 

Alexa has been available in India since 2017, but Sonos does not see the Indian market of enough interest to make the necessary investment in the server infrastructure needed for Alexa to work properly on Sonos in India. Similar decision making processes will apply to UAE, with an outcome that can’t be predicted outside the Sonos organisation.