Thomas Brewster, Forbes:

Multiple sources familiar with the GrayKey tech tell Forbes the device can no longer break the passcodes of any iPhone running iOS 12 or above. On those devices, GrayKey can only do what’s called a “partial extraction,” sources from the forensic community said. That means police using the tool can only draw out unencrypted files and some metadata, such as file sizes and folder structures.

Previously, GrayKey used “brute forcing” techniques to guess passcodes and had found a way to get around Apple’s protections preventing such repeat guesses. But no more. And if it’s impossible for GrayKey, which counts an ex-Apple security engineer among its founders, it’s a safe assumption few can break iPhone passcodes.

This does sound promising, but I’ll take it with a grain of salt. Like jailbreaking a phone, this sort of thing is hard to quash completely. And certainly incredibly difficult to prove, one way or the other.