You are right in that one can never be sure because legislation is often vague enough to allow room for interpretation, since laws have to be able to cover many similar situations. However, what I am sure about is that competition and antitrust laws do not have any sort of clause that determines how big a market has to be in order for them to be applicable. This is the FTC's guide to antitrust laws:
Do you have questions about antitrust? Read the guide for a discussion of competition issues and FAQs.
www.ftc.gov
Can anyone find any mention of the two main arguments that people are using? Namely, that consoles are different because they are not a necessity and that consoles are different because they are specialized?
In the section named "single firm conduct" the Microsoft case is used as an example.
There isn't any mention of computers being a necessity or the computer market not being specialized. As I said in a previous post, antitrust laws govern various markets of all sizes. This is why Hoeg Law has said multiple times that the Epic v Apple case is a landmark one, because it will open the door to challenging all types of walled gardens.
The most important thing in Epic's court case is not the verdict itself but the way that the relevant market will be defined. If the judge rules that the market of iOS app distribution is a separate market to the smartphone market as a whole then it will be a cakewalk for another company to argue that Playstation, Xbox and Nintendo app distribution are separate markets too.