I learned when reading Wikipedia that r- and K-selection fell out of favor with biologists decades ago; they now incorporate some of the ideas into "life-history evolution". 
I know that it probably makes sense to keep covering outdated ideas that students will be tested on in school classes.  However, it would be useful to note that the current understanding in biology has advanced. I would think this would especially help users who go on to advanced college biology.
For reference, here is a 2002 paper (23 years ago!) talking about the change: https://web.archive.org/web/20101230233401/http://www2.hawaii.edu/~taylor/z652/Reznicketal.pdf)

I greatly appreciate that the current video points out that r-selection/K-selection is a spectrum rather than 2 boxes.  Far too many adults (especially politicians) think that nature fits neatly into boxes that we humans created.