I think that if apple tries something so sneaky they’ll incur in even more scrutiny. This is a battle they can’t win, they should just give up and focus on important things, rather than anti-consumer policies.
I'll try to explain it simply.
You want to make apps for MacOS, iOS, etc? You have to have a Apple device and a Developer account. There is no getting around that. Even Microsoft Azure in order to compile apps for Apple with Azure Devops they have racks of Mac Minis that can be used as build agents. Apple is a closed ecosystem for both storefront and development. Changing the storefront doesn't change the requirement for development.
So right now as everyone likes to talk about the cost of entry isn't horrible you need a Apple Device to compile and a $99 a year developer account. Been plenty of people that have praised how cheap that developer account is.
Now of course a developer account is cheap if you make money using said account Apple makes money. That goes away with sideloading so Apple is not going to continue offering a reasonable cost of entry.
Apple will change the rules around developer accounts. There is no law stopping them from doing that nor could there be. Your developer account will cost 3% of your annual company earnings etc. It could be tiers looking at company net worth or many other options but if you're making a fortune off a developer account or in general you will pay to have it. This also kills the Epic and other argument of hurting the little guy the little guys won't pay as much while big guys will pay more etc.
Feel free to sell your app however you want Apple will still get paid. Its going to be fun seeing the hoops to jump through to get developer access. You will have to register your company and provide financials. You won't just sign up and pay $99 you will sign a contract with Apple each year with a negotiated rate. This is what the big players really wanted in the end to strike a deal instead of paying per transaction.
You can argue this all day long. You are using someone else's platform and OS to sell a product you pay for that right. That's how the rest of the world works. You will pay for the right to make the thing in licensing fees then you can sell your product however you wish. The concept that people think Microsoft or Epic is going to pay $99 dollars a year to make money on the Apple platform with no money going to Apple is laughable.
You can be Joe the basement programmer and make a fortune one year making that amazing app with millions of downloads. You will pay the following year your share or you will lose developer access and Apple is going to easily implement that if you don't recompile with a new xcode version each year even with no changes then the App simply won't work on the next iOS.
This will be the big announcement at WWDC this year.