If anything, women in relationships with those types of men are more likely to get murdered because it turns out getting a GF doesn't fix all of your problems. The former incel turns into the abusive fuckwad he always was and feels even more entitled to his partner's being. If she slights him in any way or tries to leave, he will physically hurt her.

If Elliot Rodger ever got a girlfriend, she would be in a controlling, abusive relationship and we know through hindsight he'd have killed her.