"Do keep in mind that at least one govt has successfully pressured apple to give up on its privacy"

No company can defend you from your government.

"All it would take"...

That is the slippery slope. If a government is going to say "that's a nice looking hashing system you have there, now we need you to..." they could as easily -- more easily -- have said "that's a nice filesystem you have there, we need you to...".

Hashing files and comparing them against a list is literally a college grad afternoon project. There is absolutely nothing in Apple's announcement that empowers any government anywhere in any meaningful way at all. It is only fear-mongering (or simply raw factual errors as seen throughout this discussion) that makes it seem like it does.