I think the only way to find this out in accurate detail would be to get records from MPC, and I don't think that's going to happen. I've tried to look on the MPC website, and I can't find any information stating they even drop ship, let alone from who. Both MPC and Meyer do have the same breeds listed on both websites with few differences, but it's possible that Meyer and other hatcheries can fill orders for the same breed. I've read the other threads on here and some people swear that they don't drop ship, some swear they only drop ship from Meyer, and others swear they drop ship from different sources -different opinions based on personal experience and has caused some arguments. I can attest to the fact they do drop ship from different sources because many people get packages that originated from various destinations other than Ohio, including mine. Just my opinion here, but I think if someone is going to order chicks why not just order directly from Meyer? They're less expensive, and you're guaranteed to get Meyer quality. Avoiding the middle man just makes sense.
Edit: Okay, this is what confuses me about MPC. If you read a lot of their FAQ's you get things like this:
Q: Are you a member of the National Poultry Improvement Plan (NPIP)?
A: Yes! Our hatching facility participates in NPIP...
My point is that if you read a lot of their FAQ's they repeatedly talk about themselves being a hatchery -not a drop shipper. It seems misleading.