Binary loading isn't in all runtimes (just libgdx)
yet. I seem to recall that if support were added, it would be at the very end when the file format isn't changing. For instance, the files just got an IK constraint set. search.php?keywords=binary
Personally, I've been looking into using Google Protocol buffers to generate the code for all platforms that would support multiple versions of the binary files (with optional sections) and would make updating the format as easy as editing a single file.
It's not an official plugin. I would develop it as an add-on. Also, it's backlogged in my todo list.