What happen to my chest if i dont open it?

Hello i got a question for next update. I actually have my level 13 Royal Chest. I was waiting to be level 14 to get a Champion. Since i will not be able to pass level 14 before next update what should i do ? Should i wait next update or will they just delete my rewards ? Or maybe they will give me all rewards between my level 13 into my actual xp ? Any informations about that ?

You can hold the chest for as long as you like i believe.