No, that’s not a valid interpretation of the quoted response.
If something the size of an iPad had 0.4mm of runout evenly distributed across its height or width, you would not perceive that unaided. You’d have to set it on a perfectly flat shiny surface or something, and the 0.4mm shadow gap would still be difficult to see (you don’t have to be a professional metrologist to realise this). If that figure is accurate, then the response is entirely reasonable.
Where people are claiming that their iPads were visibly bent out of the box, that would mean a deflection of considerably more than 0.4mm. So a more defensible interpretation of the Dan Riccio quote would be that he is agreeing that you should return your iPad in that case.
Whether that is in fact a real issue or not, I don’t know, but tech blogs like the Verge are literally the last place I would look for realistic reporting on Apple QA issues.
