Prismastone Rebate event

I used to play this game back in 2019. I just got back, kinda missed playing this game. So is prismastone rebate event comming soon?

Should I hoard my prismastone chest keys? How many (minimum) should I have before the event starts. Currently I have about 36 keys.

Please be nice 🙂 and answer this question. Even if there was a a previous post like this