I am sure they do. It is the strategy of all the companies nowadays, even big companies like Apple too follow these kind of strategies regularly.

Companies are using it for public stunt to make their product more popular.

Companies don't leak their own product. If a worker or someone outside of the company lets the information go when it was not intended to be released to the public, then it was a leak. That has always been the definition of a leak and still fits in this case too.