I see this hasn’t been updated in a while, but it was the first answer I found when searching for this info. So I thought I’d update with some other information I found while digging further, in case someone else comes across this.
If you right click on the video preview, you’ll find the Video Preview Preferences. In the Multicamera Editing section, you can uncheck either (or both) the Display Take Names and Display Take Numbers to clear up the preview window as you see fit.