Lovely Michiru
King Blackwater
No they don't make rigs to just tribute an anime, they only tend to make a single item in said rig.
They've done it a few times already.
Puella Magi Madoka Magica
Tiger and Bunny
Adventure Time
~ ~
oh there's a difference between tribute items and sponsors items
in the case of those you named, they are all sponsors, not like the tribute item we got from Sm when it was the anniversary last year
so we must wait for an external company to have business w/gaia to become an sponsor and maybe get a RIG like those for SM, so first they need to buy the rights to have the series... and then maybe have an sponsor here u.u
I really wish that will happen... <3