IF those wallets belong to CSW and he decided to sweep all of his BCH, BSV and eCash into single wallets he could be signalling that who else but Satoshi would have that many coins gained from forks...
The centbee micro txs could be his way letting people know he had/has 1.5M BTC but he's either unwilling or unable to do the same with the BTC 9at this point in time)

Just me thunking out loud...

I do like the theory of a Bitcoin Index but I'd be surprised if the initial index holding was that much... A smaller amount would make more sense initially which could be added to if demand increased.

So I'm going with CSW wallets showing the world he's got a lot of Bitcoins