I agree with other commenters on this topic that really this is about forcing attrition. At some point Yahoo has to make big layoffs. We all know it. They know it. They employees there know it.

Getting a bunch of folks to jump before they're pushed is a great start. It reminds me of the two Bobs from office space: "we fixed the glitch... we tend to find it best to avoid confrontation".

There are plenty of rationalizations for both sides of this decision. I lean to the simplest explanation. They're happy to see folks go.