OK so for anyone that might be interested, I had a chance to look into this and the answer would seem relevant to haejins predictions for steem and sbd.

As far as I understand it the quantity of SBD created in any given day is related to the price of the steem token. So as the price steem rises the inflation rate of SBD also rises, in theory that should put downward pressure on the price of SBD, essentially devaluing it in the same was as the Fed issuing USD devalues that.

Of course downward pressure does not necessarily mean the price will actually drop, so this does seem lend some credence to haejins hypothesis that SBD price may be a leading indicator of a steem price movement.