Sometimes it's better to split the baby
Is this a White House conspiracy to hide the effects of the law, as some have suggested? Maybe, but probably not. I have a lot of respect for the government data producers, so I am giving them the benefit of the doubt.
Yet I don't see why the Bureau needs to make such a sudden change. Why not, for a few years, give half the sample the old questionnaire and half the new one? This procedure would provide a basis for eventually splicing together the old and new time series.