Yes, mostly because no one actually cares much what anyone patents until a material invention eventuates, and partly so that they would be able to sue anyone who did actually invent it - which you will note they themselves of course did not proceed to do.

I don't claim this failed to occur because Sony is more decent than average, but because the idea is self-evidently very stupid. The thing is, when you get to have a "Patents" section in your CV, no one cares very much that they are stupid patents as long as you were working for a serious company when you got them. There is a point past which that's just a perquisite, like how the company subsidizes your au pair.

I've never needed an au pair! And I hold no patents of which I'm aware. But it is not 2009, or even 2013, any more.