I certainly agree that it is in the interest of music teachers to verse themselves in popular music styles.
I haven't checked Elena's books, but there have been many such publications over the years - in the UK, the examination boards have been selecting works by composers such as Christopher Norton, Mike Cornick and, more recently, Elissa Milne since at least the early nineties.
It's a funny little genre, really - none of it (including my own work) really qualifies as "real jazz", but what it does do is to allow classical students to explore the kinds of rhythms, modes and harmonies that are found throughout the genre, and at relatively low levels of expertise.
So, I see it as an important piece of the musical smorgasbord that we present to our students.
Having said that - the biggest problem, IMO, is that many classically trained teachers really don't have a feel for jazz and blues rhythms and articulations. You don't have to trawl through many renditions of the exam pieces on YouTube to hear that there is clearly a lot more to it than just reading the notes off the page. Some of the attempts at swing timing are truly horrendous!
But then, the same can no doubt be said about any genre of music. All part of the rich tapestry
