Invoker was in the tier list much longer than any other deck in the history. Six Samurai, Darklord, Karakuri, Crystron, Shiranui, DM.... all of them are gone.
There are plenty of reasons to outright ban this card.
No, eventually they will ask to ban Polymerization, King of the Swamp, and all other cards revolving around fusion that let players to summon Purgatrio.