Why was the M4A4 | Howl removed from cases?

The M4A4 | Howl has a pretty interesting history in CS.

It was originally part of the Huntsman Collection, but after the artwork was found to infringe on copyrighted material, Valve removed the skin and replaced it with the M4A4 | Desert-Strike.

The Howl was also reclassified from a Covert skin to a Contraband item, making it the only Contraband skin in the game.

But why exactly did Valve remove it from cases, and what happened to the cases that originally contained it?

I wanted to put together the full story behind one of the most iconic skins in CS.