Yea, people smugly think there is some cynical reason for leaks. But you nailed an excellent reason why not. The feature set is frozen quite a bit in advance because they have to line up the ability to make millions of them with bulk supply buys.

They can't "check interest" with a leak and then sell that phone in 8 months.

Most leaks are either people getting paid by industrial spies, or people who simply can't keep their mouth shut.

(Edited a word)