Dude... I'm going to go against the grain here and say embrace it.
There are worse things than taking a semester to soley work on volume. You're 170 right now... Make your new goal 200. Make you goal 10 sets of 10 on squats with 225. Work your ass off, and use as heavy a weight as you can, and get as strong as you can in those rep ranges.
You won't be able to hit your max lifts right away, you'll need to peak to get back there, but if you work hard enough and follow your coaches advice, you'll have a wonderful base and tons of new mass when you get back to lifting heavy.
Powerlifting isn't all about hitting big numbers, to really hit your potential you'll need to be at least 242 at 6 foot. At least. this is a good time to start working on it, this is a great time to gain 20 lbs. It's a marathon, not a sprint.
I'd also advise you one other thing, you now have a coach, you may not agree with everything he's saying, but you have a coach. I would advise you to memorize this phrase "Sorry sir, but do you mind me asking why?"
Make "Why?" your new favorite word, suck as much knowledge out of this guy as you can, it doesn't matter if you agree with it or not, but see his point of view. In general, seek to understand what he's saying, then seek to be understood. If you get on his good side, and show you're a level headed smart young man, who loves powerlifting, I'm sure you'll get to take some heavier weights.
But think about it from his side, he's got a 16 year old with crazy amounts of strength, and not much experience, and the kid has a itch to lift heavy... I'm sure he see's one thing and one thing only, an injury waiting to happen. He's holding you back because he doesn't want to get his own ass fired, or in serious shit, but also he doesn't want you to get hurt.
I don't believe for a second you'll be hurt, but he doesn't know that yet. Show him, prove yourself and earn his trust, seek to understand his methods. Hone your technique with lighter weights, make it perfect, ask for feedback constantly, sincerely say thank you every time he give you feedback, no matter what he says, don't ever get defensive, ask WHY?
You've got a great opportunity right now, seize it.