"בני האדם אוכלים ארוחת צהריים."
Translation:The humans are eating lunch.
I would find it hard to believe that the phrase בני אדם which is translated to the most general term of person, meaning any one of the human race, wasn't originated from Adam of Genesis (The Bible/Torah). But i guess all בני אדם have the right to thier own opinion. Whatever you believe. God will never force you to believe in His Word/ truth.
I guess what was meant is that when using בְּנֵי־אָדָם as a term nowadays it does not evoke directly Adam, like when we speak of Adam's apple (Hebrew תַּפּוּחַ־הָאָדָם or more scientifically פִּקַּת־הַגָּרוֹן protrusion of the larynx), the pictorial aspect is usually paled, although when asked about its origin, one could point out the Biblical narrative. The meaning son of man is already established as a poetical term for human being in the Tanakh (לאיש כמוך רשעך ולבן אדם צדקתך Hi 35.8 your wickedness is for a man like yourself and your righteousness is for a son of man), so that the way was free to use it as a secular term.