They don't really have a choice. The launch window is small and they either make it or they don't.
What factors are there for the lunar launch window?
It can't be weather, here, right? That's too far ahead.
Is it perigee?
If this window is missed, when is the next one?
Well at least there’s a 50% probability of success
There is a window on the 2nd. But you don't aim for the second half of the launch period and hope you make it, you aim for the start to allow time to resolve issues without waiting for the next window (which is the end of the month).