One hell of a lot of detail is missing from the Constitution on most any subject you can name.
Like I said, you're talking nonsense and requiring sellers to disclose information to buyers is a legitimate role of government.
Forcing companies at gunpoint to divulge whatever information you decide you want today... that isn't.
If it's not authorized in Art 1, Section 8, the congress has no power over it, constitutionally.
/johnny