It is certainly a departure from the previous master plans, which were informal blog posts by Elon describing Tesla’s future plans.

Maybe this is the formal groundwork for another such informal blog post, and it just happens to share the same title. Or maybe “informal blog post” was the effective medium for Tesla’s previous target audience (consumers) and “formal whitepaper” is the effective medium for a different target audience (government policy-makers?) and this indicates a change or expansion in Tesla’s target audience. I know that the US is putting out a “total electrification via renewable power” vision, perhaps this is Tesla positioning itself to be a critical supplier of that vision.