myocarditis isn't generally chronic, particularly in kids. and that study concludes that the risk of the vaccine in 12-19 year olds outweighs the risk of the virus if you bother to read it.
No, if you read the article it's from 12 up the benefits outweigh the risks, quoth:
The ACIP report projected that mRNA vaccination in 12-17-year-old males would result in 215 fewer hospitalizations and 71 fewer intensive care unit stays. Benefits of the vaccine outweighed the risk of myocarditis from vaccination in all age groups, 12 years-old and up. Our results suggest that the risk of myocarditis from COVID-19 infection itself exceeds the known risk from vaccination by a considerable margin. In light of more infectious variants, the new school year nearing and many colleges now requiring COVID-19 vaccination (either for all students or just those living on campus), these results are especially timely. Whether considering all the risks and benefits of COVID-19 vaccination or just myocarditis, vaccination appears to be the safer choice for 12-19-year-old males and females.