This is it. You’d be surprised at how high sales of seasonal lines can be months before the event.
Halloween confectionery lines should drop in the first two weeks of September.
Impulse lines (ie items in the OP) in smaller stores will have entirely sold out by November as well. Then the focus will be on the higher margin products- tubs, biscuits, gifting chocolate etc.
It seems early but it’s the way it’s always worked in retail. Easter lines usually get delivered on Nov/early Dec for the changeover after Christmas. It’s all just sitting in the stockroom waiting to go.