I don't see anything missing. What I see is you confusing Sec 1311(f)(3) of PPACA (which the the quote from the Fed govts reponse cites) with Sec 1401-36B(f)(3) of PPACA (which you quote as "Does Not Exist")Now, look at the passage used by the Federal Government in their argument as it exists in IRS Code 36B:
Hey awesome, it actually says what they say it says! It is actually the ONLY point in the section of the IRS code that mentions Exchanges created under 1321.
But wait a second... let's see how that section looks in the PPACA as it was passed by Congress:
Huh, see anything missing?
As I have been saying, the section of the IRS code that the Federal Government argues proves their claim of the inclusion of 1321 Exchanges in the subsidy plan did not exist in the PPACA as passed and was written by the IRS at a later date. The IRS is not allowed to write law.
Sec 1311 and Sec 1401 are different sections. The former has an (f)(3); the latter does not