I would think he/she means that the parties involved have made their call on their position in advance of the news. No one knows for sure the result of the data, but one can make a call what it will likely be, hence positions are taken in advance.
Have you noticed when the data is not in line with the expectation, but we then reverse the initial reaction to the news? This is because these players (not really banks) but big traders, didn't get to off load their position, hence we do the reversal.
When data is inline with expectation we jump in that direction off the get go and the same guys n gals off load no problem, then we can reverse after ( if the underlying scenario is weak).
But its not wise to think/assume that positions will always be taken ahead of data, so if one can't see accumulation then its best to step aside.
So if we work it back, we realise that news is simply an excuse/reason to satisfy the needs and wants of the major players.
So to the OP - rather than looking at what is priced in, try to see if price action can give you any clues as to what various players may have been doing or not been doing prior, as this is what will ultimately move the market, the rest is simply a form of distraction.