Former head of TAO Rob Joyce said "NSA did not know about the flaw, has not exploited it and certainly the U.S. government would never put a major company like Intel in a position of risk like this to try to hold open a vulnerability." [1]
Who knows if that's true or not, though. Certainly the U.S. government has done exactly that many times in the past (like with heartbleed).
[1]: https://www.washingtonpost.com/business/technology/huge-secu...