I don't think you quite understand Article 6 but it doesn't matter. The feds consider it a motorcycle for safety laws. The Feds have little to nothing to do with how states register and regulate them.
Here is the state law...
§ 46.2-100. Definitions.
As used in this title, unless the context requires a different meaning:
"Autocycle" means a three-wheeled motor vehicle that has a steering wheel and seating that does not require the operator to straddle or sit astride and is manufactured to comply with federal safety requirements for motorcycles. Except as otherwise provided, an autocycle shall not be deemed to be a motorcycle.

