I've heard about that, but I feel a majority of meat eaters are quite tolerant with veganism and don't see it a a threat to their masculinity. And I think I can say this threat isn't even relevant in the case of women meat eaters. About the study you linked: it doesn't really try to take an objective standpoint on the matter since its entire premise is the necessity to convince meat eaters to change their eating habits. Also is says itself (end of section 5) that the link between eating meat and masculinity wasn't specifically targeted by the study. The authors do mention though that the link between masculinity and meat eating can be attributed to perceptions created by industry marketing. But in this article (as well as in my own personal experience) this link seems at best anecdotal.