This time is very important for them--they're breathing air now, but they are absorbing the rest of the yolk in their egg.
This yolk will sustain them for the next 2 weeks while they go through their first shed, and then a few days to a week later they will begin eating.
You don't want them to come out early, because then they'll have this huge yolk sack hanging off of them, and you'll have to put them on wet paper towel and hope they can finish absorbing it properly, or they'll lose that big initial boost of nutrition.
It is cute how they use their egg as a hide, and pop back into it when they are disturbed.