Look how well your tank has done! Hats off to you!
Most stem plants don't come with roots. Yes they will root. They also take in nutrients from the water column. (That's why they develop little white roots up and down the stem.)Some of the plants appear to be cuttings (without roots). If that's the case, assume they will develop roots.
Also, do you still have any of these left and how would I submit a Paypal payment to you?