While I agree that this 'spreadable' explanation will be critical to Tau's success, I think the first stage is the technical explanation of the vision. (and resulting adoption inside the crypto community)
We are all here because of the technological advancements Ohad is working on - the creation of a better ecosystem. The technical underpinning of this needs to be shared and vetted by those within the developer crypto scene. To me, this 'developer adoption' phase is the key first step here.
I think a good analogy here is the growth/adoption of Ethereum. Ethereum is now THE ecosystem for dapps - primarily because of developer adoption. Ethereum understood that their initial target was developers experimenting and building within their ecosystem.
This could all be released at one time - packaged nicely for non-techies and crypto devs - but I think the real meat behind the bones are the technological advancements Ohad is working on. IMO, this is the critical piece that everything hinges on - not the ELI5 explanation of Tau.
TLDR - The grand picture must be packaged for the masses but, to me, it's actually the crypto community that needs to understand the technical benefits / advancements within this new ecosystem.
i agree on the criticalness of the technical materials. fortunately the hard parts will be very small, and it won't be hard to explain most of how it works even to the masses. but there's a more important intent here. we're looking for many kinds of experts, from different areas. a p2p expert might be intimidated from logic, and a logician might be intimidated from p2p. i don't think the materials should be in "heavy" language, to the possible extent. this ofc not at the expense of not showing all pieces of information.
at this opportunity let me share with you a picture i made yesterday to help me organize part of the materials i'd like to discuss (well if i already have an opportunity let me refer the readers to the topic called "belief revision" which contains results that seem to show that it's impossible to have self-amendment in a non-classical [e.g. intuitionistic like MLTT] logic):

(MADC stands for "maximally adaptable decentralized coordination", just a temporary term)