Is this speculative or does this actually happen?
As a team leader I'm involved in hiring and I certainly wouldn't treat one applicant any different from another regardless of their previous postings nor experience (except when I'm headhunting someone I've previously worked with). My own experience interviewing has taught me it's easy for people to put stuff down on CVs (eg they might have legitimately worked at Google but through an acquisition rather than hired by; or not even with the team they suggest they have). So I would consider short-cutting part of the interview process in the way you described to be grossly negligent.
I don't dispute that your CV is more likely to get short listed however you can certainly still sell yourself without having FAANG on there.
My general point is that while I don't disagree that having FAANG on your CV will undoubtedly look good, however a good engineer shouldn't have any problems getting awesome jobs with or without FAANG. Thus is the prestige attached to FAANG really equatable in the real world or is it perhaps disproportionately hyped?
Maybe this is just one of those differences between how people are hired in SV (where I haven't worked) and London (where I do work)?