I think the info poster is reasonably accurate. It's not saying that everyone will get myocarditis, just pointing out that the 5 year mortality rate after a diagnosis of myocarditis, even with treatment, is 50%. The twit (the one posting the tweet) has made an incorrect inference here, that it means that 50% of all people who were jabbed will die. That would only hold if 100% of those jabbed got myocarditis.