To be clear, its not a sudden change. It's been written into the law since 2017 that it was sunsetting.
People incorrectly assumed that Congress would extend or repeal the sunset. But its not like the tax law was changed on Dec 30th and put into effect on the 31st.
This assumes you don’t have gridlock in the House/Senate, so it’s a bad idea.
We already have govt shutdowns when we can’t pass a budget, imagine if a law that legalized gay marriage was allowed to expire, or one that granted people health care or immigration status.
Even if a non-discrimination law only expired for a short period of time, that would be enough to do real damage to people’s lives.
That way lies madness.
If the govt could do that, they could arrest anyone, anytime simply by making whatever they did yesterday retroactively illegal.