To be fair, I do indeed presume to know how the flat Earth was formed. My model of the universe is one where the Big Bang caused a superplasmic mixture of helium and hydrogen, which I refer to as aether, which has near infinite fluidity (it is not affected by van der Waals forces). Now, this aether abhors vacuums far more than other states of matter and can travel forever without losing significant energy (unless it hits something), both due to the aforementioned fluidity. Thus, there is an aetheric wind which expands into the universe, filling the infinite vacuum. The Earth rides on this wind, and has been flattened by the force of it.
If it's not affected by van der waals forces, there's nothing for the earth to be flattened against, since there's no viscous friction.
It would push an object of any shape, exerting equal pressure on all parts of it - the shape couldn't change.
You could argue that without the viscous friction, no force could be enacted on this earth whatsoever. This wind would slip off everything, why would it impart any force at all?
And this ignoring the fact that the wind would only accelerate the earth until a certain point once it's reached the same speed as the wind, thus eventually (and working through big-bang time-frames, long ago) it would've reached this speed, thus acceleration would no longer be applied. Everyone would essentially be in weightlessness.
However, considering you said this wind filled an infinite vacuum, we can assume there is an infinite amount of this wind. Thus, there would also be infinite momentum, so the wind would never lose any velocity. This means that this world would accelerate instantly, with an infinite amount of G's, and kill everyone.