Elunes Blessing question

So, with the Lunar new year event being up, and the 10% buff (Elunes Blessing), i realized it stacks with kings. Is that intented to be, or is it an exploit?
Am i allowed to go into raids/bgs with the buff? I was looking for answers on the forums/wowhead, couldnt find anything adequate.

Just a simple question, is it allowed or not?

Thanks

Of course it's allowed, it's just a world buff.