I mean, they never claimed it was to protect users. It was to protect their user's data from being used without paying Reddit. They didn't like that AI companies were using Reddit content as a free source of training data, they never gave a shit about their users' privacy.
"Soy boy" is commonly used by MAGAs as a derogatory term to mean a feminine man. There was some rumor about how soy could mimic estrogen in the body (not really true) and so they believe that eating soy products makes men feminine. This is obviously bullshit, but maybe it's somehow spiraled from "real men shouldn't eat soy" into "no one should eat soy"