It's whatever suits you for display at this point. They've grown their root mass.

If they are Darwin type and you wanted them to naturalize, color placement is easier in bloom. But I doubt the nursery trade uses Darwins for potting.

So it won't hurt them if I carefully take them out of the pot and plant them into the flower bed?

I wasn't sure I could do that without destroying the plant...

Sure you can! In fact, it is becoming very common these days for nurseries/garden centers and even grocery stores to sell started spring flowering bulbs (and not gift ones) at this time of year. They are specifically intended to be planted into the landscape and are a boon to those who want instant spring color or forgot to plant bulbs in the fall.

Just be careful not to disturb the roots unncessarily.