Does AT&T's blackout of HBO on Dish Network prove President Trump was right to be concerned about the AT&T-Time Warner merger?

New York Magazine

As Josh Barro points out, "one of the main concerns the Department of Justice raised in their unsuccessful effort to block the AT&T–Time Warner merger was that a company that owned both a lot of the television channels Americans watch (CNN, TNT, HBO and more), and systems many Americans use to get television channels (DirecTV and U-Verse), would have undue power to raise prices and withhold content. Of course, the president had some concerns of his own — but whatever his political motivations, there was a plausible case that the merger was harmful to consumer welfare, and could lead to higher prices and reduced availability of content."