Did most of people who fled Cuba after Castro took control belong to the upper class under the Batista regime, or was there a mix of wealthy and poor who fled?
" The “Historical Exiles,” 1959–62
The first postrevolutionary migrant wave, from 1959 to 1962, has been dubbed the Golden Exile because most refugees came from the upper and middle strata of Cuban society. (Members of this cohort prefer to describe themselves as “historical exiles.”) The majority were urban, middle-aged, well-educated, light-skinned, and white-collar workers. Most were born in the largest cities, particularly Havana. Many fled for political or religious reasons, fearing persecution by the revolutionary government. During this period, between 1,600 and 1,700 Cubans arrived in the United States per week on commercial airlines, and the U.S. government admitted approximately 248,100 Cubans. "
https://www.migrationpolicy.org/article/cuban-migration-postrevolution-exodus-ebbs-and-flows
They were mostly those who were either wealthy or those were were loyal to the previous regime.