30 lbs on a high school athlete - age 18 to a college athlete 2-3 yrs later is not excessive at all. A 6’-1 175 lb DB better get to 6-11/2 - 205 DB in the years 18-21 when he become a full grown man from a teenager.
An OT in high school, age 18, is 6’4, 290lbs. By time he’s a third year player, at age 21, he should have another 20-30 lbs of total weight and reduced his body fat by 45 lbs probably.
The concern is adding bad weight (fat) or not training in a general fitness and conditioning way. Bulking up does not mean getting fatter.