Another thing I notice is that many company press pages also do not have RSS feeds set up.

Some offer different kinds of press alerts, but otherwise, they are relying on people to frequently check back to see what is happening. Google does this well. They announce a lot of their news via their wide range of blogs which is a great strategy in itself, and while their press release section doesnt get nearly as many updates, they offer a feed so that users know when it has been updated. They also provide links to other pressrelated resources where their latest info can be obtained.