If it were my kid, I would wait as long as I could to see if they erupt or not. If not, you could have your dentist submit x-rays showing the teeth have not moved and there is no danger of them erupting during sea year. In another year, the one that is partially erupted might be all the way in and causing no problems.
I am not sure what dentist they are using at KP now. My DD graduated in 2021, and the dentist while she was there was a lot more prone to allowing kids to keep their teeth than when my DS was there (class of 2013).
A lot of people will probably tell you to just get them out now, but I am more of a question authority type. They will not remove the teeth at KP. You have to do it on your own dime at home. If they really need to come out I would do it over the last break before sea year starts.
Along the same vein, they will want to give your DS a ton of shots while he is at KP. Some are mandatory, but some are not. They will not tell you which are required unless you ask. Your DS can opt out of the optional shots if he chooses.