Look, I'm all for better repair options and Right to Repair, but McDonald's is selling consistency and their reputation is on the line (not the franchisee) when something goes wrong or people get sick.
For those reasons alone, it's not unreasonable to force franchisees to use a specific brand of machines, contract a specific company for repairs, and use specific OEM parts. CYA big time in so many ways.
What people are forgetting here is McDonald's has an interest in these machines working as well as possible (revenue + reputation), and the franchisee also has an interest in these machines working as well as possible (revenue). The franchisee however, does not necessarily care about the McDonald's brand and reputation, and given the option might choose degraded parts/safety to save money - causing a problem for McDonalds.
So... McDonald's says you have to use these approved machines and get service/parts from this approved vendor. Case closed...
The only people who seem to really care about this issue are customers. That won't be enough to force a private company to open the door to any yahoo repair company with Wish.com replacement parts.