no it isnt. it is derived from disparate progenitor cells.

"Two parallel neural ectoderm progenitors contribute to the developing brain"

https://www.nature.com/articles/s41593-026-02433-7

these are not separate organs these are separate "stem cell" populations.

under such a statement as submitted all of our organs that derive from varied populations of expressive constituency, would be amalgams of more than one organ.

very naive question: does organ even have a strict enough definition for discussions like this to be worthwhile?