First, leave Yale out of that.
Then, even the Haitians say:
“All Haitians speak Haitian Creole. But only 5% speak French fluently, with only another 5-10% able to understand some French.”
https://blog.creolesolutions.com/what-language-do-haitians-speak#:~:text=We%20aren't%20trying%20to,able%20to%20understand%20some%20French.
Then this comes from someone else who may or may not be Haitian:
”It is estimated that roughly 5 to 10 percent of Haitians are functionally bilingual in French and Haitian Creole. However, 100 percent of Haitians speak Haitian Creole, and, more critically,
90% of Haitians speak only Haitian Creole.”
Around 90 percent of Haitians speak only Haitian Creole. So why is school mostly conducted in French?
foreignpolicy.com
“…most teachers have low French proficiency, the Haitian state demands children acquire educational content by means of a language nobody—not even the elite—is willing or able to speak.”
Around 90 percent of Haitians speak only Haitian Creole. So why is school mostly conducted in French?
foreignpolicy.com
"Even today [...] Haitian children are still subjected to a school system that largely operates in a language few Haitians speak with competence—let alone can read or write.”
Dr. Hebblethwaite addresses the disparity between French and Haitian Creole in official policy
www.latam.ufl.edu
This is why whenever you hear someone say most of the Haitians that they know speak multiple languages, what they are saying is that most of the Haitians they know aren’t like most Haitians since the vast majority speak one language.