Two thoughts:
What would Satoshi think of sidechains?
(Hint: I suspect he likes them ... )
What if someone(s) involved with Blockstream is Satoshi?
Now it is all out in the open, like the source code, which for sidechains, does not even exist yet.
Cool a speculation thread with people talking about SC, I read the paper the other day and almost cried. This is truly a thing of beauty, I remember writing on my notes: 21Million BTC | ∞ SC Assets
Alot of smart people working on that team/with, likely he has been involved at some stage unbeknownst to all or most.