A suggestion isn't the same as prohibition -- he was informally advised that it wasn't worth the teeth gnashing from fans; not that he outright couldn't write a critical article. Beyond that, criticizing a song that uses multiple samples for having a high number of credited writers is stupid to begin with and really wouldn't be worth digging into. If anything, Bey and her team going out of their way to make sure every contributing source is appropriately credited is a good thing; there are multiple instances of sampling in her music where she could have easily gotten away with just closely mimicking the inspiring source (Stevie Nicks' guitar riff in Bootylicious, Boyz II Men's down count in Countdown etc.) and not crediting the original artist.
Anyway, I agree that Bey is a difficult person to publicly criticize; she doesn't give much ammunition -- she's legitimately talented, incredibly hard working and very well behaved/graceful -- and plus she'll never,
ever respond directly so it will always be a one-sided thing usually making the person coming for her seem petty and nitpicking at best or a flat out bully at worst. And combine those elements with the fact that she has a notoriously visible and outspoken fanbase, and well, yeah -- the few angles you have to scrutinize as it pertains to Bey really
aren't worth going for at all.
She's not immune to negative press by any means tho and any valid opening the press get to go for her, they gleefully take it.