Does saying "be right back in 1 hour" mean I'm going to be back in 1 hr? or does it mean I'm going to be gone in 1 hour?
That's an example of Internet slang, but not strictly though. Be back in one hour is simply a shorter way of saying I'll be back in one hour which means that the person will leave and after one hour they're going to be back. I'll is left out because that way the thinking goes it's "supposed" to be faster to type things into your computer when there are fewer symbols in a sentence. You see this used a lot mostly by people who make use of instant messaging apps to text each other over the Internet.