Yup! Besides the special event items, you'll see summer related items sold during summer, winter during winter, spring during spring, etc. Sometimes you'll see them mixed up, but most of the items are related to the current season.
Tbh, I don't really believe that's the case but since a lot of users say this is the case then I guess i'd have to agree also. Although I did see able sisters selling a long sleeved sweater in spring..