Your first link is extremely prudent at drawing conclusions. it may well be that too much consumption of pornography decreases one's ability to get to the same degree of arousal in real life. But the meta-study doesn't say anything about the effects of being exposed to pornography as a teenager, and even suggests that these effects are only temporary: quit watching that much porn, and you'll do better.

Your second link is about correlation between consumption of pornography depicting violence against women, and expressing views supporting violence against women. It does not say anything about causation. It's not very surprising that men who support violence against women would consume pornography depicting exactly that.

The two links you provided say absolutely nothing about porn exposure as a teenager. Even if there was a detrimental effect (which the 2 studies don't say), it doesn't mean that monitoring and filtering is an efficient solution, especially at the expense of a healthy relationship with your kid where they trust you enough to have a discussion about something that shocked them.