Because “freshman” has the word man in it.
I wonder if they are going to replace the word “woman” as well?
Yale administrators consider replacing ‘freshman’ with gender-neutral term ‘first-year’ – The College Fix
Since apparently there is nothing more pressing than stressing over “proper” language, administrators at Yale are pondering eliminating the term “freshman” and replacing it with non-gendered “first-year.” “I think there comes a time when you want to make sure that the way you’re calling things reflects the values that you have,” said Dean of Student Affairs Camille Lizarríbar, who is “leading the conversation” on the issue.