How did they not know about these requirements? I know this just by seeing the endorsement disclosures everywhere I see someone on video talking about a product

How did they not know about these requirements? I know this just by seeing the endorsement disclosures everywhere I see someone on video talking about a product. It's sort of like knowing that requirements for cookie usage is a thing just because you see the acceptance forms everywhere. Or that you could work out that stop signs are a thing because you see everyone stopping at them.