AC Milan has been a declining/aging club with no evidence of getting better anytime soon. They aren't known for developing youth well, given Pato has been there for a few seasons and is only turning 21 this september. I dont feel like he'll become half the player he could be surrounded by the players at AC Milan or in that style of play. I dont want the same to happen to Neymar.
Of course he wouldnt do nearly as much without that service. Do you think Messi or Eto'o would of scored as many goals the last few seasons without Xavi, Iniesta feeding them and Dinho before that? He's not that good in the final third yet b/c he's just 18 (lack of experience) and needs to work on his shot (staying accurate when using power). When given a sliver of time he's very good at placing the ball accurately, with both feet. He's similar to Robinho at the moment but like i said, he's only 18. He can develop more physically and has the pace/dribbling/two feet to be a more direct scorer like Pato. Robinho's size doesn't hold him back on being more of a direct scorer, his chosen style of play does. Villa is a great example. And I never said he was great at passing.
Either way, like I said and Kluivets agrees, he's not ready to leave yet. And yea, if he does leave next year it shouldnt be to a major club/league yet. Pato was a more mature player at his age, and although he turned out well for AC Milan, he's nowhere near where his development should of been.