AFAIR that WSJ exposé is recent; if so, this is not a reaction to this - last year, I've been working on some code integrating with GMail, and I remember encountering the announcement of this change 6+ months ago.
EDIT: at least I think I do. I tried to find a reference to this in my project note, to confirm the timestamp, but I failed. So it could be I've seen it in October 2018, as 'Ivoirians pointed out.