To use the read-aloud function in Edge on a Mac you do have to have the developer version of Edge installed. Anyone can get that version right here.
Applications for Education
One of the things that I appreciate about the read-aloud function in Edge is that students can customize it to meet their needs. Students can not only choose the voice that reads aloud to them, they can also choose the speed at which text is read aloud to them. The other nice aspect of Edge's read-aloud function is that the words on the page are highlighted as they are read aloud.