This is bullshit and nothing more than a petty attention-grab on the part of the store's owner.
I think it's pretty neat that they're a vegan café as I know my vegan coworkers are sometimes a bit limited in terms of which nearby restaurants have decent vegan grub, but this is just some bored liberal trying to get into the news.
It's kind of sad, really. There are plenty of things worth protesting. The wage gap is a real thing, and it's fucked up that it exists in this day and age. But the answer isn't to turn around and be discriminatory towards men.
Any reasonable feminist would be appalled at the behavior of this café, and rightly so.