That was just one example of managing out that is clearly no where near "constructive dismissal". There are lots and lots of levers that management can pull to either reduce or increase attrition, and lots of them are about the employer choosing not to give extra support rather than taking away the basics. The normal attrition rate at an average company is already 10%, so pushing it a bit up isn't particularly difficult, especially at these big tech companies that traditionally have done a lot to try and keep people.