Peace TLK
You are right! However, this is just another example of the opinion of the awaam that outshines the opinion of their own scholars. Being esoteric the Barelvis focus on such statements, but because their awaam are non-the-wiser they assume the meanings to be literal. Also, the high-street mawlvi will be likely to enforce these beliefs.
The actual scholars of Rai’ Barelvi do not share in this opinion.
The shadow or no shadow argument due to taqleed on the matter, people have erroneously reiterated the material given to them. The source of this idea is based on two narrations which are not supposed to be equated. To have no shadow does not mean that it is made of light. Rather it means that the object is transparent. So the logic in that deduction is not fool-proof.
It could also be argued that from other narrations that a cloud used to hover over the prophet Muhammad (SAW) to shield him from the sun, then it is obvious that he had no shadow, because the cloud was in the way !!!
The essence of Muhammad (SAW) is light, what that essence means now is another matter and should not really be debated.