collectibles AND special items after summer event?

[czezz]

Does anyone know what happens to summer event collectibles AND special items (eg. foul, tackle, etc) after summer event is finished?
Will they be discarded or only hidden until next summer/football event?

[Areop-Enap]

From Dev Diary:

Resource and item exchange
Event currency will be removed from the game and exchanged for 1 Gold Coin each
Tactical resources are removed from the star menu, all storages and mail attachments without compensation
Tactical buffs are removed from the star menu without compensation
Event adventures are removed from the star menu and mail attachments without compensation