I have been aware of the difference for as long as I can remember, since my mother grew both, but grocery store labels seem to include "sweet" when selling peas-the-vegetable.I have never in my life ever heard someone call peas-the-vegetable "Sweet Peas". I have only ever heard that term used for the flower.
My local grocery stores have both frozen peas and canned peas labeled "sweet peas."
Here is an example of a brand that I think is available all over the USA:
https://www.delmonte.com/products/vegetables/peas/sweet-peas
So I can see why some people, especially those who do not grow flowers, would think that "sweet peas" means the things they can eat. It's confusing and occasionally may be dangerous, but I don't think there's anything we can do except be very clear about the different any time the subject of safe-to-eat comes up.