It was previously thought that Zayn would compete in the 50 man Royal Rumble match. However, Zayn is of Syrian descent, and Saudi Arabia and Syria broke off all diplomatic relations in 2012. Immediately, people began speculating that Zayn was held out of the event to avoid upsetting the Saudi Arabian government.
One wrestling site reported that Zayn himself requested to not be part of the show, but it turns out that is inaccurate. Instead, Pro Wrestling Sheet reports that Zayn was held out of the show in order to respect the local Saudi Arabian customs.
WWE also issued a statement, which reads "WWE is committed to embracing individuals from all backgrounds while respecting local customs and cultural differences around the world."
This is also the reason that WWE's women were not allowed to be on the show, prompting all kinds of criticism toward the company given their public persona as an organization that has been pushing a women's revolution in the wrestling world. It was just a couple weeks ago that they released a WWE 24 documentary on women's empowerment. To hold such a highly publicized show in Saudi Arabia, which banned their women's roster from being part of the show, looks more than a little bit hypocritical.
It's no secret that there are all kinds of women's rights problems in the nation of Saudi Arabia. Women were not allowed to attend Greatest Royal Rumble unless they were accompanied by men, and they were only allowed to sit in certain sections. The government likes to claim that the country is slowly changing through their Vision 2030 initiative, though that plan has skeptics. In fact, Zayn has wrestled in Saudi Arabia before, so the fact that he was held out of Greatest Royal Rumble would seem to indicate that the country is moving backwards.
It's not just women's rights issues that are the forefront of the criticism WWE has received for their Saudi Arabia agreement; the country also considers homosexuality a crime that is punishable by death. Yet just three weeks ago at WrestleMania, Finn Balor made an entrance accompanied by rainbow colors in a message of inclusion for the homosexual community.
Greatest Royal Rumble was the first show in a long term agreement between the WWE and Saudi Arabia, so these kinds of criticisms will be on-going for years. WWE is making an enormous financial profit (the exact numbers won't be known until this summer) off of the arrangement, but the price they have been and will continue to pay when it comes to public relations could prove to be enormous.