I mean really, the "avalancher" part is a direct to connotation to the fact that he gets stronger with time (i.e. escalates) which is exactly how an avalanche works in real life. Not really following the rationale for replacing his signature and defining ability (i.e. escalation) for what is apparently frightful blows. I mean c'mon, he's a physical base attack champ with range 1. How threatening could escalation really be on him? Consider that all the other champs which currently have this ability have attacks electricity, psychic, fire, and magical--and considerably longer range I might add. Of all champs, yeti avalancher should be the first champion with this ability. The fact that he had it initially and it was then removed just leaves me more confused about this. Am I completely missing something here?
No, I would say you aren't missing anything. Even ignoring the "flavor" reasons, he's pretty bad and could use it.
I seem to remember him more as a Manic champion with Freezing Aura rather than for Escalation. Regardless, he's a very different flavor of yeti now than he started out. Definitely a rune that could use some revisiting.