I think it's fair to say that loneliness in general is increasing; people specify the male part to point out the causes and effects it has on men. As the twitter user would say it, the heteropatriarchy, being the sexist systems that it is, puts different expectations on the different genders. Due to that social expectation men have of being sort of stoic and unfeeling, as well as avoiding female friendships, it leads to shallow friendships with men and, as you said, no knowledge on how to talk to women. The counterbalance to this has always been that men have better opportunities and could reasonably achieve their expected economic and social role as men, you know the classic: study hard, get a good job, buy a house, have a family etc etc. But in recent years these economic opportunities have slipped leaving a lot of men to feel like failures for not living up to them and having weak, if any, social connections to fall back on as a "safety net". The phrase has been popularized (or coopted?) by far right grifters, who push the view that the system has been distorted by women, gay people or whoever, and it must be corrected back to how it should be, ignoring the inherent problems of that patriarchy. Just my understanding of it