> they now have total command of supply

They've always had control by licensing who can publish games on their platform. Now that contract with publishers has changed who can distribute. Publishers are still free to distribute on other platforms in whatever formats those platforms allow.

> that market being Playstation games

This is arbitrarily narrowing the definition of market as far as possible while ignoring reasonable (legal) thresholds. Case in point how Apple's App Store was not ruled a monopoly while Google's Play Store was - there are reasonable tests to pass, and Sony's case will land closer to Apple than Google. And a monopoly is not the only form of anti-competitive abuse.

Might as well claim Domino's has a monopoly on Domino's pizza.