I see this move as rather idiotic, regardless of Sony's motivations.
If it's because of the Switch, they should know that Nintendo not only might surpass that 160m figure without moving a single more finger, but in case they struggle they will very likely just cut the Switch's price. And that would put an end to this stupid question.
If it's not because of that (PS Anniversary/Whathever)... Then they are incompetent and dumb. It's been almos 12 years since the last sales update. Are we supposed to believe that they were just sitting on this information for that long just to reveal it now? Or are we supposed to believe that they just figured the 160 milion thing recently? Either way its... Dumb. Very dumb.
No matter how you put it. It's so fucking dumb. This makes them look like fools from every single point of view xD