User blog comment:ChishioKunrin/RWBY Volume 3 Livestream/@comment-119.252.112.70-20160212011925/@comment-4010415-20160212013454

To be honest, Monty wasn't the only person who planned the story of RWBY. He worked with Miles and Kerry, and together, the three of them planned it all out. They outlined the plot points and all that.

All that really changes is that they try to translate the plan into episode format, and sometimes they realize that what they thought was going to fit into a single Volume actually won't fit, so they have to move certain things to the next Volume, like they did with pushing Volume 2 plans to Volume 3. They've also said that sometimes, they look at one of their plans and go "Oh, that can actually happen right here instead, and it'd be better, so let's do that!" And sometimes they look at a plan and go "This absolutely has to happen sometime before that because that event will change things to where this plan wouldn't be able to happen, so there's a deadline for this plan."

Stuff like that.

So, it's not that Monty left behind notes on ideas for the story. It's actually that Monty, Miles, and Kerry planned out literally the entire story.

Aaand I wish I could remember where I heard all of this from, but I know it was directly from Miles and Kerry and such. Though, I believe that this explanation may be gathered from information given by them in various different places.