One less wife available for men leads to anger for those without one.
Incels already exist and at the same time the most attractive men have a wife, a mistress, and occasional hookups. So it Wildente necessarily change much. Except the side pieces could have actual rights and more societal respect by becoming wives.
Men are far more susceptible to be victims of violence, addiction, suicide, incarceration, mental illness, loneliness etc. already.
High male population nowadays is usually caused by elective abortions.