That's not original and not funny, I'm disappointed...
That said, the agatha upgrade thing seems cooler, it's more like a new and funny mechanic to me (even if already exist is some way with spellstones)
That's how they introduce almost every mechanic. They make a card without keyword, see how the community reacts and if it's positive then they create a keyword with the same effect for the next expansion and expand it to multiple cards and classes.
They did this with unstable evolution and echo recently, overkill was also created this way.
It's great that extra arms effect become a keyword, I don't see what's boring.