Given that your source is the Bulwark, no, it isn’t.

This seems relevant: https://www.thebulwark.com/p/violence-hatred-americans-warped-beliefs-values-polls

The reason tragedies came to be associated with tales of woe with sad endings in later audiences’ eyes is that the all-important big decision at the end was almost never a happy one. (One exception of which I know? Sophocles’ tragedy of Philoctetes ends with the titular bowman being reconciled to his comrades and commander who’d abandoned him and returning with them to the Trojan War where we’re told he goes on to win fame and glory and—most importantly to him personally—full healing for the painful snakebite on his foot.) In many ways, this original definition of a “tragedy” is how the vile vermin currently expressing their admiration for Charlie Kirk’s assassin online and in corporate and government halls of power are trying to spin their narrative of this capital criminal being some kind of “tragic” hero: “He had to do it! Kirk had it coming for being on the wrong side of history!” (i.e. “How dare he win debates against us and our narratives!”)

Something long forgotten by those who use “tragedy” in the currently popular manner to mean “calamity” as you describe in your article is that epics can be calamitous tales of woe with sad endings too. For instance, Homer’s epic Iliad and Odyssey stories were pretty calamitous for the Trojans, as particularly detailed in Euripides’ The Trojan Women. More recently (albeit still well over a century ago now), the real-life epic that came to be known as World War I followed this formula to perfection, beginning small with a hotblooded petty partisan’s assassination of Archduke Franz Ferdinand and opening out into a gargantuan tale of misery and woe for an entire generation of young men in Europe’s nations and their many allies and client nations all around the globe as particularly detailed in Erich Maria Remarque’s All Quiet on the Western Front.

Where this current real-life story of Charlie Kirk’s assassination will take us, neither you nor I nor anyone else can know for certain. As with the attempt(s) on President Donald Trump’s life, the current fury may pass as the demonically hateful far-left partisans currently celebrating Charlie Kirk’s murder are deservedly isolated and marginalized: dismissed from employment, drummed out of polite society, and thoroughly discredited in the eyes of all civilized peoples as we dismantle the corrupt and evil institutions that spawned them. Alternatively, as with the far-less-admirable (yet still undeserving of assassination) Archduke Franz Ferdinand’s murder, the fury may spread and grow into a worldwide conflagration if the perpetrator and his admirers are not properly punished for the murders they’ve attempted and committed and—most importantly—are still inciting others to commit.

Either way, your assessment is accurate: Charlie Kirk’s assassination is no tragedy. It is an audience-participatory morality tale with no shades of gray in which Kirk’s family and friends and admirers are the good guys (though not the heroes; those would be Charlie Kirk himself, and whoever ultimately avenges his murder) while the assassin and his admirers are the bad guys—the villains who do evil deeds for evil purposes because they are evil. Whether or not this tale of woe turns epic, for those of us out here in the audience, our tolerance for these villains and their victim-playing sophistry is at an end.