I know a number of people who have had broken engagements and went on to have wonderful marriages with their right match.
He was not meant to be with that other girl or else he would be.
It is her parents job (and hers) to check him out thoroughly. She will not thank you if he goes on to marry someone else and they are happy.
Unless you know something truly egregious about him, like he is c”v taking drugs, stealing, nasty, it would be uncalled for to get involved.
All you criticize is a matter of perspective and opinion about him. She knows his level of education. They can ask about his level of learning.