I guess the slang has changed, AFAIU “goon kit” was a go-bag for stuff you didn’t want to be identified for, like if you were doing a very silly prank like egging or TP’ing someone’s place

Change of nondescript clothes, stuff you need for the game, but stuffed in a disposable jansport so you didn’t wince when you have to abandon it behind a fence

Now it’s just……whatever the hell THIS is