[Update] Disappearing Hot Time Box Rewards

Not liking this, sounds like a method to try and reincorporate hot times.

Now, once every while's ok

I don't know what you're getting at. How does it sound that way, and even if it was, why would it be bad?
Try to think of why Hot Time events happen in the first place. The primary purpose isn't to hand out goodies; if that were the case they'd just have them available for pickup over an extended period of time instead of having tens of thousands of people all logged in at the same time.