Creating a new Branch requires that you specifically address people in the To field. This is akin to writing an email. You have to know whom you're writing your message to. Does Branch plan to replace the so-called void in email? If yes, I don't see any compelling reason to have a Branch. Besides, I don't see a way to have a private Branch yet and even if there is a private Branch, I don't see why I should create a Branch here when I can easily compose an email.
However, there is a way to create a Branch addressing to yourself, which counters the above situation where you have to address someone specifically. More below.