Wayfair is not and has never been your typical tech startup. The founders didn't even take VC or give out much equity until soon before their IPO. Given their conservative behavior, I'm not surprised they looked at the diminishing returns of hiring more engineers to work on AR/VR/whatever flavor of the moment and decided to cut costs. Because at Wayfair, engineering is just another cost center.
Having 350 more engineers on the market is only a good thing. Salaries in Boston have gotten to the point where an engineer with no experience just out of a middling CS education can demand $120-150k and often get it. Where does that leave most (non-startup) companies here? With inexperienced and understaffed teams.