The homeowner will roll out with a gun and immediately be killed in a hail of bullets, despite acting entirely within their rights. No ICE agents will face any consequences, and the warrantless raids will continue. That's what usually happens anyway. The 2nd amendment is a farce; law enforcement can legally kill you for exercising your right to bear arms if they want to.
See the Breonna Taylor case or one of the many, many instances where dumbfuck no-knock raids got a cop put on GoFundMe. If the gun owner survives the encounter, they're likely to be prosecuted for not magically knowing the home invaders were cops, or not believing "Police! Police!" (because everyone knows only cops can shout that). The cops will definitely shoot back, though, and there's a high probability that the gun owner will not survive the initial encounter. Still, if enough cops get put on back window stickers, they'll start exercising some discretion.
One the same day Rittenhouse got off, a guy who defended himself against this exact thing was acquitted. But since the weapon he used wasn't properly registered to him (a charge which the judge for Rittenhouse shrugged off and tossed on a whim) that guy got 30 years in spite.
They'll find the loopholes to achieve the desired outcome.
In most of the US, there is no legal requirement of registering a weapon to a person. I think you're confusing that with the Wisconsin law restricting the unsupervised use of dangerous weapons by those under 18.
A solid majority of the 2nd amendment crowd will immediately ask what they can do to lick the boot harder. Those motherfuckers love jackbooted authoritarianism as long as it's aimed at the right minorities.