Note that I teach tech topics at the university level, in an art school. That means a mixed audience of people who have a hard time with programming and complete nerds, but didn't come here for semantic definitions, but to get shit done. To get everybody on board with such a topic requires you to start small and on a literal "explain this to a 5-year old"-level.
Of course when teaching this to our sysadmin or someone more knowledgeable I could take your approach since I can assume they know the priors and even have seen a regex or two.
However most people don't care about any topic except when it solves their problems in ways other solutions couldn't. And this needs to be the first thing you show them. Why are regexes really awesome for certain problems that commonly exist. Bonus points if it is a problem they already encountered or are currently having.