I think the point is that young women are vulnerable to predation or abuse no matter who they date. We read the stories all the time.
Women are victims of intimate partner violence and of stalkers, rapists, murderers, dudes they meet online and date, who decide to kill them, fake Uber drivers, real taxi drivers, boyfriends, husbands, etc. Most of the women who go missing and are found either alive or dead after having been harmed and/or abducted had nothing to to do with dating older men.
I don't think this lifestyle makes women any more vulnerable than they already are.
The only complication I can see is that if a man involved in a relationship like this harmed his female companion, it could be much harder to trace if he was being clandestine, because they don't want wives to find out. So they might use snapchat or use burner phones themselves, etc.
It could take time to untangle that for evidence needed to find a perp.