I see nothing wrong with Taylor wanting to improve their own remote monitoring UX. That's just how competition works. Kytch make a good app, and what is Taylor supposed to do, not improve theirs? That part of Kytch's argument is bull. Kytch can MITM and reverse engineer Taylor's machines, but then they don't like it when Taylor does it back to them? Seems like a pretty weak argument. Both companies just need to focus on engineering a better product.
One might expect franchisees have the right to repair their purchased equipment, even if forced to purchase specific food sevice equipment as part of their franchise agreement. One would not expect their equipment provider and franchisor to collude against them.
The missing piece is the kickback to McDonald’s, or a similar financial incentive from Taylor to maintain the status quo. I imagine that’d be a component of discovery or information requested by a federal regulator.
If it's the first (and I think it is), then Taylor has every incentive to make the machines as reliable as possible. Service calls are expensive and most companies don't make a lot of money doing them. OTOH, a service contract (e.g., maintenance contract in software) is often lucrative because the customer is buying peace of mind. Years can go by in which the contract isn't needed and the seller (Taylor) pockets the cash, but the buyer keeps paying for it because it's cheap insurance.
It makes money leasing real estate, and equipment to franchisees.