Using /ei/ can help students remember a series of words, such as play, stay, day, today, away, say, etc.
Oral English class is set up for exams, emphasizing oral English, so there is no conflict between the two.
It's just that the oral exam needs sentences, not words.
Kindergarten children learn, and there is no harm in learning. Children are educated from different angles.
Learn English with interest. One is expressed in sentences, and the other is memorizing words.