Hoarding Knowledge

Steve Rubel in his post Edelman Acquires Valley Tech PR Giant A&R Partners indicated the following.

I am really looking forward to meeting the A&R team and their clients. Many of these companies are already blogging so I will be really interested to hear about their experiences and what we can learn from them. Welcome A&R!

I’m confused by this statement on two accounts. First it sounds like since they’ve "assimilated" these people, they are no longer their enemy but their friends now. The question I’m wondering here is why is knowledge sharing only occurring when someone is bought out or acquired? I mean why couldn’t they share knowledge even as competitors? Wouldn’t it make the entire PR industry all the better if they did? Secondly, if these guys have blogs wouldn’t he already be hearing about their experiences, as wouldn’t they be talking about them on their blog? Or do they avoid sharing the new things they’ve learnt from blogging?