I think you're neglecting to remind folks that Matasano would give people a crypto textbook to study from first.
So if a VB programmer were applying for a React job, you'd say, "here's a React book; we're going to have you code a React component during your interview. Let us know when you're ready to schedule."
Google does not hire with a work-sample test. tptacek's claimed process is therefore easy to distinguish from Google's. Maybe better, maybe worse.
Google does allocate non-trivial time on training, though, both on the candidate's time before the interview (as you note), and on paid time after hiring.
So if a VB programmer were applying for a React job, you'd say, "here's a React book; we're going to have you code a React component during your interview. Let us know when you're ready to schedule."