It's ok. Milk is still important for their development but it's no longer the star of the show. My 28month daughter only drink 1 cup of milk per day. Just make sure he eats his solid well. Continue to serve iron rich food like fish, meat, beans etc
My son refused drinking milk at 2 years. I was make sure to give him other dairy food like yogurt , butter , cheese
It’s okay! Milk is a supplement at this age. Can increase other dairy product or high calcium food!