Hey! My son is 36" now at 7 so though I can't wait to bring him to WDW in 8 days!!! I am not looking forward to telling him no to most rides. Kinda was hoping in his teen yrs if he isn't too much taller he could still ride. Thanks for the reply! Disney is still awesome so I know he'll enjoy it!
First, is there more growth in height that can happen for your new son or have you've been told this is it, more or less? If there's hope for a little more height he may be able to do more later in years at Disney. There's plenty to do at Disney World without ever going on a thrill ride.
I'm not sure about the ages of the others in your family, but you can easily avoid the areas of the so called thrill rides; so, your new son doesn't even have to see most of those areas. Avoidance may be good tactic for a while. Hopefully, it's not really an issue for the moment; so, enjoy this trip before the realities have to set in.
You may have to have a heart to heart eventually about the realities of his situation at Disney World and the rules there of, but for now you get to enjoy your time at Disney World without much issue at 7 years old with him. You may have to break up in smaller groups; so, those who can do the thrill rides in your family will without your new son having it in his face. Then, you can enjoy other attractions with him while the rest get their share of the thrill rides.
If it's too hard you may have to find new adventures for vacation where your new son won't have those same challenges.
Over the last 5 years we had to change our way of doing Disney and we concentrated on more shows, live entertainment, parades and fireworks. We enjoyed our time there without the thrill rides. Disney is still very magical without the thrill rides.
You have great courage; bless you.