Expedited removal is part of their existing authority to deal with fraud and misrepresentation with visa entry requirements.
It only requires a few hours to process and results in a five year ban from the United States as a deterrent. Detaining someone indefinitely under these specific circumstances is not something that happens in France and Germany. And until now wasn’t something that was happening in the United States.
Formal deportation does not require imprisonment for weeks, I personally know someone deported on arrival from Spain and they were sent back to their home country a few hours later. There's no reason to do it, it costs more for the country deporting someone, it doesn't improve the deterrence since the deported will be banned from entry for a while.
> but based on the German election results, there's no hope.
Hopefully European nations will reform their immigration system based on this, but based on the German election results, there's no hope.