After over a decade, the original poster is lost to time. Nobody will ever be able to properly claim they created Herobrine - meaning, for as far as we will ever know, he is Mojangs’ property. (Unlike the backrooms, which is a novel concept and is public domain, Herobrine’s story is set in Minecraft, meaning it is not public domain).  
Rumours are, he will be in Minecraft Movie 2. If they are already willing to acknowledge him outside of Easter eggs and ‘removed Herobrine’, they must be willing to capitalise off this IP.

My idea - this movie is not set in the world of Minecraft, but in the real world somewhere between 2011 - 2015, when Minecraft was old and creepy. Unlike A Minecraft Movie, this is not a world where Minecraft never existed either. This is just our world. Basically, some kids play Minecraft, they find Herobrine, he somehow begins to affect their lives in the real world, they defeat him. My proposal is to imply he was a rouge AI, but with room to speculate he was supernatural. I also suggest that he doesn’t ’destroy Minecraft’ at the end. The timeline continues as normal, nobody finds out (although it’s implied Mojang knows the truth), and the last scene is modern day Minecraft where Herobrine somehow returns, war of the worlds style.

Now that popular internet urban legends are becoming movies, can we please have a Herobrine movie?