The ACLU is not wrong, they are right in the technical sense.
But I very much doubt you would practically manage to remove that NAND chip and replace it very often on that umpteen layer ultra thin board. Instead, remove it once and stick it in a test fixture, then try brute forcing it.
"Technical correct... the very best kind of correct!"
The bigger question here is: do you really want law enforcement to hack into things as standard procedure? They certainly don't. It's difficult, expensive, slow, and worst, unbound by law. It's a world where your privacy is exposed based on the federal hacking budget rather than a judge's opinion about your potential criminality.
It's much better for law enforcement to be constrained by law than technical ability.
But I very much doubt you would practically manage to remove that NAND chip and replace it very often on that umpteen layer ultra thin board. Instead, remove it once and stick it in a test fixture, then try brute forcing it.