It isn't just a nod to the old "bring a knife to a gunfight" phrase; it's an amendment to her 2017 "Call It What You Want" lyrics. That song was Swift licking her wounds, still reeling after her own cancellation. In it, she declares, "my castle crumbled overnight / I brought a knife to a gunfight."
With this change, eight years later, she's acknowledging the criticism she received around that time and is taking ownership of that era of her life. She was throwing a pity party for herself, busting out a tiny violin, which only brought more outrage her way.
Part of the fun, though, is another Swift tool—allowing herself to play the villain. Here, she adopts a "Blank Space"-like attitude (fitting, considering her Showgirl producers, Max Martin and Shellback, also produced that 1989 hit). She mentions that she likes "her whiskey sour" and "poison thorny flowers," before adding "Can't you see my infamy loves company?"
She notes that these moments leave you forever changed—in good and bad ways. "Now they've broken you like they've broken me / But a shattered glass is a lot more sharp," then reiterates, "and now you know exactly who your friends are."
The song combines the edge of Reputation with the lyrical wordplay of Red, and in doing so, she reveals how the "cancelled" era of her life strengthened a core value: loyalty.
From "Actually Romantic" to "Eldest Daughter," she touches on feelings of betrayal, but the invisible string connecting it all is knowing who you can count on through it all (yourself included). "Cancelled!" crystallizes that sentiment in a way that makes you want to shout the lyrics in your car, full blast, letting you linger in the delicious pain of the moment for just a bit before you're ready to, ahem, "Shake it Off."