It wasn't titled that for very long. The current title is "2021 Waukesha Christmas parade attack." It had been changed from "attack" to "crash" ands then back again.
Wikipedia is like any other crowd-participant site: you get all kinds. The Wikipedia page was created just before 02:00 GMT on the 22nd, and there have already been over 700 edits to it. There's one twit in particular mucking with this page, user Harizotoh9, who wants to fight with and reject any edits that reference Fox News or the NY Post (but he/she thinks MSNBC is the gospel), or, basically, anything that paints the attacker in a negative light, and he/she has been deleting the word "attack" and similar. Also interesting is that a photo of Brooks was removed at one point; evidently because he doesn't fit the profile of what the left want to see as a mass murderer.
To Wikipedia's credit, they do have the big splash section at the top of the page that says, "This article documents a current event. Information may change rapidly as the event progresses, and initial news reports may be unreliable. The latest updates to this article may not reflect the most current information." I never look to Wikipedia for news...meaning rapidly evolving current events. They aren't a news outlet and don't pretend to be.