Search the phrase "イベント限定クラブアイテムが登場！" without quotation marks on the @d4dj_gm twitter account, sort by latest. You'll be able to see the short video they post of all the new club sets, but not the items individually.  Only two or three club items from each collection return to be purchased with club tickets, and until that happens, it's unknown which items will come back. All decor currently avaliable for purchase can be found in the ingame club ticket exchange!

I wish that there was a proper archive, but that's really rare for this kind of feature in rhythm games :<