For idiots who don't know how to market well, perhaps. Leaking is a no-win for the company.

If the leak is true, then on announcement day, nobody is impressed or surprised because it was "Nothing unexpected. Yawn". News outlets may not even bother to note the announcement.

If the leak ended up getting exaggerated, then on announcement day it's nothing but disappointment, "That's it?!?!?! They were supposed to mega-feature!". News outlets might talk about how the manufacturer is struggling and had to "drop features". Looks bad.

But if you can get a new feature out that people did not expect, then people go "Wow!". There is chatter online. News people might make a story about it.

tl;dr leaks are like telling people what they will get for Christmas in advance. If it's true, it ends up being nice, but no real joy or excitement because of lack of surprise. If false, nothing but disappointment Christmas morning.