You need to do your homework of finding everything about this guy and his family . People are known to have multiple women from everywhere and run prostitution rings.
Nobody other than An Arab living in UAE can be citizen of UAE. If they sound like someone from Pakistan and claim to be UAE citizen that might be a lie.
I am being skeptical as you are against this rishta , so please , please , please make sure that they are what they are claiming to be.
Other than that Urdu accent of someone should not be a deal breaker. Ever Urdu Speaking folks have many accents.** Ever heard a Hyderabadi **or Bihari speaking Urdu ?
I think that having linguistic skills/culture of a certain type or standard is a perfectly valid requirement, if it is important to you. I don't think you should dhaanp down what is important to you. A style of speaking or communicating is important because all marriages need a lot of communication to succeed. Are you so old and ugly that this guy is your last chance?
I'm not saying reject him automatically. Meet him, see how you feel about him in person, but do not compromise on that which is important to you. A style of speaking/culture is just as much a part of someone's beauty as big eyes or a nice physique -- as is the soul/mind/character they are communicating with that style.