If they have no covers the game will be off as no way a frosty pitch would be passed just after the sun starts rising.
If they do have frost covers, then perhaps it is to see if the frost covers have worked or not. My experience of these at another club is that there is always patches or join lines where they haven’t worked.
I remember us playing a Christmas game back in the 90s against Orient where it was frost free except for a treacherous patch down near the PopSide (shielded from the sun by PopSide roof) and no way it should have been played as it couldn’t take any form of stud.