What could you possibly teach about touch typing besides just telling people to do typing tests or write papers over and over again?
People aren't bad typers because they weren't taught. They're bad typer because they dont type.
Recordings are one of the worse ways to store knowledge for later reference, except in usual scenarios. They're very awkward to work with. The only plus is their cheap an easy to make.
Trust me, I work at a company where "documentation" is often an old meeting recording (and sometimes you have to count yourself lucky to even have that).
I had a boss that typed with one finger on each hand, it was laughable, but he was an incredible programmer, so it didn't affect him at all.