Excellent article. I agree with most of this. I would say that the FTC has little real authority in these matters. It couldn't stop the acquisition. It sued to ask the courts to stop the acquisition. And even that it did only because it's led by someone (Kahn) who philosophically believes companies buying other companies is bad (just an ignorant and economically destructive position -- acquisitions, even among larger companies, fuel the M&A market which drives startup innovation and investment). Under other leadership (probably just about any other leadership), that case would never have been launched. She had no real legal basis for her position. The judge, appointed by the same person as Kahn, so as friendly a judge as she could have hoped for, basically called her case meritless.
That doesn't mean MS could acquire Nintendo, just don't take the words and reasoning of Lina Kahn as evidence that they could not.