No, it's like walmart demanding that suppliers of a house alarm which has an associated subscription (e.g. alert response service) also give them a cut of that subscription, or else.
I can't be too open, but I work with a firm that makes IoT products, sold at retail, and as part of the contract a retailer was granted a percentage stake in the attached subscription service since otherwise the margins weren't sufficient for them.
There's no reason that should be illegal. A contract is a contract is a contract.
I disagree that any contract is valid - sometimes they're illegal because they abuse the near monopoly power of the retailer to force suppliers into contracts to their detriment - the choice is either accept the draconian terms or go out of business. Very much like Apple's message to hey - nice app you've got there, shame if something were to happen to it.
This is why we have (or had) antitrust laws - not every contract is legal and left alone capitalism tends towards abusive monopolies.
