I am hearing a lot of people who are not young discuss this topic and I would really like to hear from young social media users whether or not this would have any effect on them.
The article brings up this:
Critics of the proposed warning label seized on this point. They ask, “Where is the series of definitive scientific studies to prove that social media and phone use destroy teens and adolescents?” They want the same kind of proof that eventually jolted our public health response to tobacco: blackened lungs, cancer research and thousands dead.
I don't agree with the critics personally, but if I were their age and I saw a Surgeon General's warning about social media when I logged in, I might wonder why they're doing this when there's no conclusive evidence of harm.
I should also point out that Surgeon General warnings on cigarette packages began in 1966. You can see here that there is definitely a steady trend line downward, but it had started long before the warnings began and the warnings don't seem to have been a big factor, since there wasn't a huge drop once they started. It went down for women after it had been going up, but it had already been going down with men and I am not convinced there is a strong correlation with the packaging and women.