This is good advice. To go from a good situation with coaches and teammates to one where the level is higher but the coach turns into a douche and or the teammates don’t click will make for a painful season of regret.
Try to be open minded, you could be biased if you only had limited interaction with a coach and how he runs practices and games. In the end, go with your gut feeling and make the best out of whatever you may experience. Your 7/8 year old is already ahead of most kids of the same age, so as long as he is being pushed and have fun, it doesn't really matter much if he goes to elite or T1. He will eventually be playing at his level.
Not sure why this is even a question. You can’t be concerned with “level” at mite and squirt. Find the program that is offering the better coach and go with them.