To me, it is fairly clear the IRS guidance is correct according to how the law was written.

If the Senate Finance Committee wants to criticize somebody, they need to criticize themselves (and the rest of Congress) for allowing the law to be passed as written AND for not passing a subsequent law to clarify/correct things.  But the fact that they are blaming the IRS/Treasury for something that is their fault, shows how clueless they are, so I'm not holding my breath for them to change things anytime soon.