From my perspective, he is probably referring to chromeOS’s crosvm container, which virtualises a debian install (or other distros). Since Chromebooks are popular in schools, predominantly in the USA but even still globally, students are likely to attempt to gain further functionality out of their devices, and hence experiment with Linux, get used to it and possibly install it on different devices (or on that same Chromebook through the mrchromebox firmware) in the future.