The fact that Haven is Caydee's younger sister has been much discussed in skating coverage over the years.
And I don't think Haven and Brandon are being ignored. They have been recognized as rising stars for years as well. The recent addition of Steuer to their coaching team has gotten lots of attention, for example.
During his commentary for one of IceNetwork's backstage shows at Skate American, Coughlin spoke very enthusiastically about the special excitement that Caydee and he naturally were feeling as Haven/Brandon competed so well.
Etc., etc.
BTW, Golden Skate itself recently published an article about Haven and Brandon, IIRC.
No law says that any skater has to be active on social media, but to draw a contrast:
I think one of the reasons Carly and Gracie Gold receive a lot of attention as twins is that they share lots of photos and messages about their activities together. Carly tweeted at least several times about Gracie competing at Skate America -- cheering her on, and even showing Frank Carroll's reaction to Gracie's SP spin, for example.
Caydee tweets very rarely in general, and I don't think she posted anything at all about Haven competing at Skate America. Haven does not have a Twitter account, AFAIK.
Max Aaron is not a super-frequent tweeter either, but he did give a shout-out to his sister Maddie on the occasion of Skate America -- making her GP debut with Max Settlage in pairs.
The Denneys seem to like to keep a low profile. Nothing wrong with that. But it means that they are not giving the media any family "color" to latch onto.