The author misunderstands what FSD reversing is. It's about backing OUT of parking spaces and being able to autonomously perform maneuvers like three-point turns. HW3 can already back into parking spaces using autopark without needing to shift, only using screen controls. Also HW4 does not even yet expressly back into parking spots at destinations, even though it has happened once for YouTuber "AIdriver" at a super charger, it was a fluke, and is not consistent or described as a feature.
Tesla is trying hard to shoehorn the latest FSD v13 edition of its autonomous driving software into vehicles with older Hardware 3.0 computers, and is notching some successes.