Did they offer any reasons why they closed it?
I didn't really use it myself, but it was funny to read some conversations in there sometimes, usually absurd speculation that was often dead wrong...
Yes. They posted this in the NOTICES tab:
"To meet the increasing demands on support staff, the Trollbox has been disabled indefinitely and moderators have been reallocated to assist in support."
Which is something good because their support is very bad and they take days to answer a simple support ticket, while the trollbox is most used to overhype coins and pump shitcoins. I'm sure I'm not gonna miss it.