In the case of something like Theranos, I thoroughly agree. Oversight of a commercially available product, especially one with health implications, is definitely necessary. Although it seems even these systems failed in the Theranos case.
If they say they're going to sell trucks, and they present a truck doing truck things (moving), most people would assume it's a complete truck as portrayed. An empty shell is just fraud in the court, hopefully.
It's not a good look, but you also shouldn't be investing based on what amounts to a commercial. This should be another stain for the company and another warning sign for investors, but we don't need a law against misleading promo videos because almost all are short on information and high on emotion. It's the investor's job to get the information behind the video.
As an example, if you apply for a bank loan and falsify the application, you can still be charged with fraud and go to jail even though the bank potentially could have discovered the falsehood by hiring an investigator before issuing the loan.