They've already confirmed in their wired articles that PS4 games are backwards compatible sothis wording suggests that not all are playable not that they're jot boost mode compatible.
we shouldn't start with word twisting right now already, just as we saw what this did with all the expectations towards the GPU.
stop it right there.
this sounds like not every PS4 games is PLAYABLE like the exact wording is saying it.
so don't infer meaning into this.
if all PS4 games are playable at launch Sony will clarify this pretty soon I would guess, so let's see and wait. because as of now the wording sounds like not every game is playable