I guess it must be important if the VGC Ghost is talking.
Maybe it's just me, but this is important how? I mean, maybe there's some supply issues and some last minute changes, but nothing major I don't think.
I would assume the implication is that because the devkit is larger and the games have not been shown playing on a stock PS4 yet that the size of the console they showed may have been over ambitiously small and this will cause problems perhaps with overheating.
That said I don't recall if any prelaunch showings have ever been on stock consoles.