I can only speak from my experiences. A 9u player needs to play on a team where when he gets up in the morning he is excited to either go to practice or a game. He is looking forward to being around his friends and coaches where he is allowed to dream of being whoever his favorite MLB player is.
Now if the player has talent maybe exceeding his peers at this time then maybe he plays on a higher caliber team to play against better competition . A 9u player needs to play at his skill level... maybe that's rec league maybe that's the elite 9u teams... if there is such an animal.
I would say in this day and age you need to play on the best travel team that you can where the following criteria is met. ( any order)
1.) playing time ( whats the point if no one sees you play )
2.) competition ( play where you are at least in the top 1/3 , too little and you do not grow, too much and you fail)
3.) finances ( do what you can afford)
lastly, I would do this as a rising freshman.... too much growth and changes to worry about anything until then and even then so much will change year to year. as a freshman you get a year or two to feel out the process
Now if you can afford to throw tons of money around play for whoever