I realize that you didn't ask me, you asked the OP, but I will give my reasons for using a suppressor, especially with new shooters.
1. It takes away the muzzle blast, which in my experience, is the main contributor to flinches with new shooters. People generally attribute it to recoil, but it is actually the muzzle blast that is unnerving to most new shooters.
2. It mitigates the recoil. Added to the benefit of no muzzle blast, you now have the best of both worlds.
3. It eliminates the need for hearing protection in the field, thereby allowing for better communication. Unless you honestly don't care about your child's, or grandchild's, health, they should be wearing hearing protection in the field. Even one gunshot causes hearing damage and that damage is cumulative. If you don't believe me, I can show you the last results of my own hearing test, which shows my right ear has normal hearing, my left has "Severe" impairment. I always wear ear pro at the range, most of the time double, but 35 years of shooting animals in hunting scenarios before suppressing everything has left me in this condition. When wearing hearing protection, it is very hard to communicate in quiet way necessary in the field. Yes, you can wear electronic hearing protection, but those also amplify wind noise and other background noises to the point of distraction. Having nothing in or on your ears is the best way to get clear communication.
4. You can hear the bullet impact. A lot of times with new hunters you have to make a decision when the shot opportunity comes up. Do you watch the animal looking for a good hit, or do you watch the shooter and coach them through the shot? When shooting suppressed, you can watch the shooter because you will know through the sound whether you got a good hit or not. It is very similar to bow hunting. When you hit the chest cavity you will hear a "whomp" sound. Hit the guts and you get a different, more hollow sound. Hit bone and you will hear it crack. Even at extended ranges, you can still hear the bullet impact. Now, the best case would be to have video on the animal and you watch the shooter, but in the absence of that, this way is the next best. It also allows you to hear the animal run through the woods if it does run. No ringing in the ears or "dead time" as your ears readjust to normal sound. I have found more than one animal solely due to the fact that I could follow it's run through the bush and hear it crash.
So, those are the main reasons why I recommend a suppressor for hunting, especially for a youth or new hunter.