Gruber and the amicus brief he signed were cited in nearly every government court filing in both the King v. Burwell case and the Halbig case. In fact, a metaphor which Gruber often used to discuss the ACA, comparing it to a three-legged stool, was adopted wholesale by Judge Edwards in his dissent in the Halbig case.
But as Sam Kazman at the Competitive Enterprise Institute noticed, "in this latest document Gruber is gone." His name and his metaphor are completely absent from the government's filing last Friday, which opposes the Supreme Court taking up the King case.
It's not hard to figure out why. Back in July two recordings of public speeches were discovered in which Gruber indicated subsidies would not available to states which do not set up their own health exchanges. After claiming the 2012 statements were "speak-os" Gruber dropped out of site.