Even if, as some predict, the Y chromosome is nonexistent in about 5 million years, some other mutation will have to replace its function. Otherwise not only is Darwinian Evolutionary Theory wrong, our species will not survive.
And I like men, so it would be sad. Maybe not the ones who drive gigantic pickup trucks to overcompensate for their tiny penises, or the idiots on Steemit convinced there is a "LGBT Agenda™", but in general ...