Recently, I read New Yorker article entitled "The NBA and China and the Myths of Sports Democracy," where the author argues that international competitions like the Olympics have had virtually no diplomatic value. Have there ever been instances where a country's government bolstered democracy, civil rights, or civil liberties as a result of hosting and/or participating in an international sporting event?
The most obvious counter-example, surely addressed in the article you mention, is South Korea in 1988. There have been some very detailed posts about this already, such as this by /u/AsiaExpert
To your broader question, it’s probably fair to say that hosting such an event can help tip the scales in a country with a lot of unrest and strong social movements, but does little on its own.
I’d also strongly suggest checking out Chalmers Johnson’s 2000 book Blowback, in which the formerly conservative political theorist turned anti-imperialist discusses the various negatives of US support for brutal right-wing regimes such as South Korea’s. He devoted a section to the effect of the Olympics specifically.