It's time Bitcoin fans gave up worrying about the US government missing out on those mad gainz. I'm sure the government will do just fine but feel free to donate to them if you're getting sleepless nights over it.
It's not just any old prick who can bid. You had to pre register and put money down otherwise it would trolled into the ground. The people who did bid are hardly going to be worried about the government knowing where the coins go or disguising their origin. They'll want to preserve that stamp of authenticity.