As someone who lives in the Emirates, I have to object to the allegation of "slaves." This is not slavery. It's indentured servitude, which is definitely distressing but not quite of the same character. Most importantly, in the talks I've had with workers, the vast majority of them still are happy to have these jobs despite the conditions. They're paid an order of magnitude more than they make in Nepal and if you go…
Do you think they'd be paid in full at the end of their period? From the pattern of treatment described in the article, I'd expect it's common for them to be left unpaid or underpaid at the close.
Unpaid, no. It's extremely rare for an employer to not pay anything ever. Underpaid, definitely—between extra "fees" and deductions, many workers end up with less than they expected (but still more than they'd make back home).