A: Congress used to be able to establish regulatory authority in the executive branch to manage details like this, because writing a useful law that covers this in any detail would be impossible. Thanks, GOP-stacked Supreme Court, for wrecking that.
B: This administration doesn't give a rat's ass about the law, so none of this would make a difference anyway.
That's been the problem both times this administration was in power. Some people like to call it 4D Chess (because they don't understand it and their conspiratorial thinking requires there to be "a plot" or "a plan"). The last person to get to the ear of this President is the cause of any new "process" or "policy". It is just whim. Like a dog seeing a squirrel. Something shiny has attracted his attention. And that new squirrel gets chased.
That said, there is stupid "making it up" and smart "making it up". But it does need to be made up.