With all monopoly/monopsony discussions, it all comes down to the degree to which the monopolist leverages their position. It's not illegal to have a monopoly, only to abuse it.
Nintendo, Microsoft, and Sony each compete rather vigorously to attract studios to produce games for their platforms. Nintendo classically has ups-and-downs in this arena, given their unconventional hardware choices. The Switch is attracting a lot more devs than the Wii U ever did, for instance. This breaks the theory of monopsony, as there is clearly competition between platforms to acquire games.
Contrast that with the App Stores on phones where everything feels incredibly static. Apple and Google are clearly coasting on the fact that there's only 2 phone OSes and you have to use one of them. Besides first-party apple stuff, there are hardly any exclusives. And you never hear about app devs changing platforms.
So I would conclude that no, Nintendo, Microsoft, and Sony don't need to be regulated because they aren't engaging in anti-consumer behavior. They should be subject to the same standards, of course, but they aren't currently in violation of them like Apple.
