This is super interesting.
Whom is a great question. But so is: Why?
I mean... the implications of this move are powerful. The person doing it obviously has a lot more bitcoin than the coinbase of this block. And if they wanted to fire 40BTC off somewhere for any "normal" reason they would not be picking *this* block.
Who is it?

And what on Earth are they doing this for?
I have a feeling this move is the prelude for something interesting... but then again it could just be someone moving coins around... because... umm.... umm....
A lot of interesting question this one started indeed.
I've seen assumptions that owner of these just wanted to buy a nice house so he probably believe that was post-halving peak.
I personally hope that whoever it is he just sent these old dusty bitcoins to some charity reasons (because owner of these has a bunch of btc for sure)