From what I could tell, the 'standard' for reasonable commute measures from the employee's home, not from the original location to the other. But the federal WARN info says 'reasonable' varies by locale, and didn't offer any specifics.
Moving the office is probably neutral or better for people on the Penisula. And may be neutral for parts of the East Bay. Depends on where exactly in San Jose the new office is too.
Also, I was surprised by how light traffic was when I drove from Mountain View to SF last October during what I was expecting to be the morning rush hour. I don't recall what the reverse direction looked like, though.
But my point was kind of to raise the likelyhood that this action was taken without regard for how it looks, and without regard for required notifications.