The real assumption here is that facilitating communications will help drive up traffic and thus ad revenue. A commendable initiative by Facebook if you are one of their investors.
Well, as has been demonstrated time and again, there is not always a conflict between "private" / "market" interests and "public" / "community" interests, nor need there be. (Arguably, there's almost never a clash unless the market interests are coupled to political ones, but let's not get into that...)
I'm not saying so much that there is conflict, but I very much doubt that the Facebook people truly believe that this will have any real effect on world peace or that their motives are anything other than money.
No, the assumption here is that facilitating communication will help resolve a conflict. A commendable initiative by Facebook.