[quote=@Prince of Seraphs]
<Snipped quote by RWBY Wiki>

Should Skyra, Grane, Gren and Geni be worried about this?

[@PyroDash888][@Nytem4re][@Lucius Cypher][@LokiLeo789]
[/quote]

Gren is quite aware of this, but relies a bit on being in Beacon and mostly on The God Eater to deal with the White Fang. That and as far as Gren knows, the White Fang don't have the weapons and manpower to try something like an assault on Beacon, or sending assassins for hunting down deserters. Of course Gren is also completely unaware of Cinder's existence, and would be as surprised as Blake to see the Fang cooperate with humans. 

It may come up at some point as a side plot, like what Skyra wants to do. Gren still has a few siblings running off to the Fang, so Gren hasn't totally escaped them, but as it is the White Fangs severance policy is just another reason for Grant, Grant, Geni, and Skyra to keep quite about their former affiliations, less a spy or something catches wind and takes them out. Or for someone to sell them out.