What happens with the new bulbs of your pics if you let these shoots grow and then they freeze in winter?
It never seemed to affect the winter hardiness of the bulb itself. A quite surprising observation, I would say. Leaves and stems always froze green, as orientpets often do here, also. When a green shoot was still growing froze, as with the right bulb in my pic, I am not sure how the bulb responded the following spring. I suspect the it just produced a completely new shoot, but much later in the season.
I don't know if this is a "tropical bulb" trait. Not many people grow Lilium neilgerrense, for instance, to know.