McCourt, who says that he has no interest in becoming TikTok’s C.E.O., is unique among the group of potential buyers. For starters, he has been steadfastly public, voicing his desire to purchase the app in print and televised interviews, including on “Fox & Friends,” reportedly Trump’s favorite show. He is also the only potential buyer so far promising to serve the public’s interest—to address not only geopolitical concerns about the app but also the deleterious effects it has been shown to have...