Whether a 7-year-old sees adult content accidentally, intentionally, because of peer pressure or any other reason, I still think age appropriate sex ed would be helpful. I acknowledge that minors do view inappropriate content and that it is generally unhealthy, but since it can happen, and does happen, a good approach would be to educate them preemptively.
For example, these guildelines for sex ed in EU, which caused some outrage in conservative circles a few years back, suggest that "sex in media and dealing with it" is a topic for 6 to 9-year-olds.
Of course you can't cover every outlier, but can you really stop 5th graders from sending weird shit to their friends because they're trying to be edgy?
Edit:
Another way to think about it:
Was the content accessed accidentally? If so, I would argue this law misses the point and better moderation would be more effective and also less, y'know, surveillance state adjacent
Was the content accessed intentionally? In this case, sex ed would probably help