All broscience. The original study was even interpreted wrong I think.
I get chronic migraines and used to think it was from MSG, but it was from the high fat content of foods that I was eating with MSG. My mother in law cooks with it and I never get migraines from her cooking. I make a few of her recipes at home and toss a bit of MSG in there too and no migraine at all. I think it's all placebo, as well as people eating extremely shitty, high sodium, high fat foods and violently pointing the finger to MSG.