Despite teenagers having mobile unrestricted access to all sorts of supposedly corrupting media available to them at all times, they still make rational decisions regarding their bodies. This is very encouraging to all those that value freedom.
This theory doesn't make sense (and I read three articles that repeat what you say). If you use contraception, you won't have pregnancy. So why are the rates down? Health? Then why are 25% of kids obese (I looked up those figures). I can only assume that technology has created more social isolation.
You're saying technology didn't spread the idea of having less sex; I don't even think the commenter you're responding to claimed as much, merely that for all the chatter about sex and violence on TV and video games and other media, teens are still doing a good job at not making stupid choices. Which is contrary to what many people believe today.
I don't think technology has very much to do with it, more the idea that if you're born into a household with five other starving kids, you're less likely to repeat what your parents did.
And, absolutely not. Tinder is legitimately causing hookups that probably wouldn't have otherwise happened so easily, just as an easy example.