This actually started a couple of years ago, but is getting worse since the price of oil is going down and they need to tighten their belts (and hire locals so that locals don't get into mischief).
Saudi Arabia’s new Crown Prince, Mohammed bin Salman bin ‘Abd al-’Aziz al Sa’ud, will deliver the most significant forced population move of the century — allegedly some 10-million people — as part of his bid to return the Kingdom to economic viability. Official data shows only some 8.5-million non-Saudi workers and families are resident in the Kingdom out of a total population estimated at 32.28-million. But Crown Prince Mohammed — and most external analysts — believe there are substantially more foreign workers in the country, perhaps even double or even greater than that number.
But what will happen to Pakistan (and India and Indonesia and Ethiopia and the Philippines) if they start deporting deporting tens of thousands of their foreign workers whose remittances keep their families alive (and pay a lot of the school fees and help the families build decent houses etc.
The Philippines has over a million in the area... and this Feb 2017 article has some recent details of why they deported 40 thousand Pakistani workers..
one of the hopes is that since Duterte is cleaning up the drug trade and scaring local politicians into being honest, that we will soon have more locals jobs for these semi skilled workers.