Contact OZ and ask since they have seen many and should know better than others.
3 months out of flask is no long enough time, but none of them show any mottling at all, then it might be a mix up. Or they all just happen to be late shower.
My venustum flask with over 30 seedlings in it, I would say about half of them were faintly mottled and the other half, plain green.
After a little over a year now, all of them have mottling, but some have it sharper than others.
I have also seen both species like sukhakulii and Maudiae type hybrids with zero to very faint mottling at flowering size.
So, there is obviously huge variation but entire flask being zero mottling seem a bit odd, although possible.
Ask them and let us know.
I'm curious.