I'm not entirely sure it was necessary, it's not like someone is rushing to put out an Orzhov shadow or Esper shadow commander because, ugh
Jamie McCrimmon also curves beautifully into an old favorite of mine in Surrak, the Hunt Caller
Other diabolical interactions include Dark Wings Bring Your Downfall plus Breath of Fury, I Am Never Alone in a Kiki-Jiki, Mirror Breaker deck, My Crushing Masterstroke plus sacrifice outlets, and Approach My Molten Realm with either my boy Heartless Hidetsugu or Malignus
In the article announcing the banning, Wizards suggested that it was willing to see if players would tolerate a "skill-testing, one-deck metagame." As such, it seems that a deck being 75% of the format doesn't automatically necessitate a banning

Green Earthcraft/Squirrel's Nest on loose paper Historic White/Blue/Green Defender on loose paper Historic Black/Red Death's Shadow on loose paper Historic Emry Blue/Artifact on large loose paper Historic White/Blue Flying on large loose paper Historic Red Goblin Tribal on loose paper glued on playing cards Historic Blue/Green Merfolk Tribal on loose paper glued on playing cards Modern Green Treefolk Tribal on loose paper Modern Black/Blue Ninja Tribal on loose paper glued on playing cards Modern White/Blue/Black/Green Snow on loose paper glued on playing cards Modern Black/Red Elemental Tribal on loose paper glued on playing cards Legacy Black Reanimator on loose paper Of course, playing MTG can be tricky, especially when you can't ask for help or seek rules clarification