John, thanks for the detailed reply.
You asked what my concern is. My concern is this - we are building a product that enables users to write HTML pages where the <script> tags (and <script src>) tags can be es6 code (this is not the main gist of the product, but only a part of it). We transparently compile the scripts into es5.
Obviously :-), we have been using traceur to compile the <script>-s. We're compiling offline, and so not using traceur's ability to compile the scripts on the fly in the browser. And it was decided to compile all <scripts>-s from es6. Just as if all script tags have a type=text/traceur added to them. It was also decided to enable import statements in those script tags. This was not difficult, as traceur includes specific support for this (it includes them inline, browserify style).
If what I read is true, then we will not be future compatible, as import statements won't be supported in script tags, but only in <module> tags.
Would you know where these decisions are (or will be) made? Is there a public mailing list, group, or forum where this is discussed?