Twitter buyer Elon Musk calls himself a free speech absolutist, but that could be put to the test in the Middle East where critics say authoritarian governments use the platform to track opponents and spread disinformation.

In a region where the local media is often controlled by the state, millions of people rely on social media platforms to follow news and express their opinions.

Both Twitter and Facebook showed their potential to influence real-life events during the 2011 Arab Spring uprisings when they played an....