Hmm, sorry I may have been misleading in my comment.
. It's not really the starting of solids that is going to make him sleep through, but if he's truly waking out of hunger, the more he takes in during the day the less he will wake. He's likely not taking enough solids now to really make a difference.
If you're starting to think that he doesn't really need that bottle, you can always try reducing it by an oz every few days and adding that oz to a day time feed. He could also be waking at those times due to develomental stuff going on, i.e. all the rolling and getting used to sleeping in different positions. Once you go to him, he may eat because he's hungry enough to do so, but wasn't actually waking out of hunger, iyswim. Have you ever tried to resettle him at those times without feeding? Ultimately, I agree with Noa. I'd give the new routine a week or two to settle in and go from there.
