I think it is too early to tell on these first year stalks, but stalk strength seems adequate. They aren't completely vertical (as is usual) but no parts of the stems lean more than 45 degrees, most in the 30 degree range.
I don't have L. henryi now. It was one I grew from a NOID tiny bulblet gifted to me as a teenager. On that one, the stem was very strong, but the upper half naturally grew to near horizontal. It was not among my favorites. L. rosthornii is blooming right now (thanks Ramona!), and its stem is completely vertical.
From L. henryi, of course there is variation, and some have dubbed certain clone(s) "erecta" for their stronger, straight stems. It is certainly a characteristic that needs "improvement" in the general henryi population.
I would guess that aurelians would, in general have sturdier stems than L. henryi, as trumpet species that cross with it do possess stronger stalks. I am not sure if the following is true, but I have always thought of henryi as being a lower elevation lily, while the trumpets of aurelian ancestry are higher in the mountains, often growing on cliff sides.