Yup, I've been in the workforce for quite a while and I don't think I've heard the term before. I generally avoid marketing types and try to avoid new product launches because I don't like all the BS the marketing departments come up with to try to sell me on their half-baked crap (I usually wait for independent reviews).

So if I've heard it, I've tuned it out. I've heard of "demo reel" (i.e. when trying to get sponsored as a skateboarder or whatever) and "show reel" feels familiar, but not "sizzle reel."

In my line of work (software development), video is rarely the desired format for anything, and certainly not as a demonstration of skills. We largely work in text, and if you asked me to make a demo reel of something, I'd have to spend some amount of time looking up how to do that (I haven't edited a video in decades, aside from short screencaps). If I ever need to do that on the regular, I know it's time to retire or find a new job...

If people are going to be dicks about not knowing the term I'm going to be a dick about knowing the term.