Transpiling (as much as I hate that word, because the more you know about compilers, the more meaningless it is), is about source to source translations, not binary translation.
And they have a first pass AOT, with a JIT backup from the sounds of it to support JITs like browsers, node, and java.
And they have a first pass AOT, with a JIT backup from the sounds of it to support JITs like browsers, node, and java.