I assure you they were not just imagined but warned against.More sunny uplands. We now don't get early EU alerts about dangerous foods, along with not getitng early terrorist information either. Whatever people were signing up for, I am not convinced these things were ever imagined!
https://www.independent.co.uk/news/uk/politics/food-safety-brexit-imports-salmonella-b2081022.html
But "project fear"....