When I left, the pay office did offset what was in my provident fund (not including their contribution) against what they saw as my liablilities. You are required to leave a further AED4000 'on account' for any unforeseen liabilities that may arise after you leave the UAE (Guess what, they managed to 'find' a medical bill that did just that!)
I found the extraction process every more convoluted and unwieldy than the induction process - if that is possible!
All that said, the money I paid to leave EK was worth every penny.