Looks like Legend is coming soon and most likely on December 6

Hmm..

The pirate king treasure event started from 23rd of June till 6th of July.
The monkey doll event started from 30th of June till 17th of July.

The first Legend update along with Cannon Shooter was released on the 7th of July.
Those are the dates for KMS.

And gMS got Big Bang part 1 on 7th December as well, I think they started patching on night of 6th Dec PST. So it would make sense if we get the patch on the 7th day. The patching time seems to be different now though, so not sure.