In the " $match: Filtering documents" section, the commentary at about 1’14" appears to refer to a “$test operator”. I could not find a reference to $test in the MongoDB documentation. I downloaded the transcript and, yes, the $test operator is referenced. It was only when I got to the “Key Things to Remember” screen in the video at 2’48" that I surmised that it was meant to be $text.
A quick look suggests to me that you’re correct. I’d recommend using the “Report an issue” tab at the bottom of the screen to report that. Those comments go directly to the curriculum team, who are the folks responsible for fixing anything like that. Thanks.