The total number of job opportunities in two countries over the span of the ~50 years they have been major oil producers is necessarily less than the number of opportunities available in an entire continent + one of the largest nations in the world over a period of centuries.
Almost 90% of the UAE’s population consists of migrant workers. The U.S. can’t get anywhere near that. Since people flock to countries with free speech, then the UAE must have extremely free speech laws. QED.
Of course this is as wrong as your original claim because seeing where people migrate is not a reliable indicator of whether their destination has “free speech” or not.