I believe he mentioned that they are going to be listed on Steem Engine which makes total sense. There is no reason not to have them also on SE.
What it does is it enables people who are earning SE based tokens to use them in SMTs without having to go off the SE platform.
Now that you mention that, ive heard that before. Not sure if he told me are i read it somewhere. Thanks for the information man. SMT's are gonna be fun, i looking forward to it :)