What, Apple advertises sleep and then decides "you know what, even though it works fine, and is heavily used, and is essential for enabling laptops to be portable, which is the only advantage they have over desktops - we should just stop that from working"?

Or is this more of a "Who's going to notice that the functionality they use every day has been disabled?" kind of idea?

The only feature here is that you're no longer allowed to do something that was an important part of how the computer worked. That's the headline of the press release, and the goal of the software.