I wonder if the message conveyed would be different if we rephrase it another way:
> Organizations allowed in included ABC, CBS, The Wall Street Journal, and Bloomberg. Journalists from Breitbart News, the One America News Network, The Washington Times and Fox News, all with conservative leanings, also attended.
Also, I think NYT is playing with the word "allow" here. By saying "Organizations allowed in included X, Y, Z. ... A, B, C also attended", this gives the false impression that A, B, C are somewhat "not allowed" by separating the list into "allowed" and "also attended". This is obviously false since they attended it.
Now I wonder, if my aunt had balls, would she be my uncle?