I don’t understand. Direct purchases from developers is allowed. E for Everyone is for Microsoft products only. Everything sold in the Marketplace is sold by Microsoft, and everything sold by Microsoft conforms to the E for Everyone rating, therefore, they can sell MSFS as E for Everyone. If you modify it by buying 3rd party software, that is the customer’s responsibility for what software is installed on their computer.
As long as nothing in the description and sales material from the Marketplace shows the weapons, they are selling what they say they are selling, and they don’t have to say anything about what configuration of the software might be if you were to buy it elsewhere.
That’s like complaining that the car you bought at one dealership doesn’t have the same configuration as one you saw at a different dealership. It’s up to the user to do their research on anything they purchase, anywhere.
Sorry, it’s just the way things are.
That’s one reason why everything from the Marketplace goes to the OneStore directory, and all 3rd party software goes in the Community directory. There are other reasons, but that’s one.