I think this is great advice. While I've only contributed to a couple open source projects and haven't lead my own large ones, I completely agree. There's more to submitting patches than writing the patch- understanding contribution guidelines (code style, documentation, testing), responding to feedback, etc, these are all extremely important in actually contributing to a project. And having even just that little patch merged in feels great when you're starting out.

Plus, no one wants to make a big helpful functional contribution only to be thrown away because they weren't aware of how the community operates. Small patches have a low risk as far as learning about how to contribute, even if the patch is rejected for whatever reason.

Though this seems somewhat obvious, it's nice to have it stated and validated by the leadership of one of the largest open source projects.