Almost everyone lets toddlers play with toys that say "Choking hazard: Ages 3+", because that warning comes on basically all toys, including stuff like Jenga blocks, sidewalk chalk, ....
Any parent who disallows their child from playing with any “age 3+” labeled toys/objects before age 3 is going to be significantly delaying their child’s development of basic fine motor skills.
Some parents might become desensitized to the labels since the warning is used over-broadly, and might not realize that tiny magnets are something you have to be extra careful about, because the effects of swallowing magnets are generally worse than the effects of swallowing some little piece of plastic.