Odds are (and this is speculation on my part) they are waiting for the Australian release - which is the EU region device.
And will consider 2 out of 3 'good enough'.
Right now they are catering to a crowd that can only use 4.x devices globally.
Increasing their target audience to both Japanese aswell as EU-region devices significantly increases their market share.
And considering the fact that Gateway cards have always been regionfree, it shouldn't be that big of a leap for an american user to import a New 3DS from australia.
You'd have the english software, you'd have region-free functionality from Gateway (assuming that persists) and if region-free isn't available from the start you can use the EU-games which are also english.
That way they won't lose out on waiting another 2~3 months untill the actual EU/US releases.
Not to mention, odds are EU and US devices are already in production and probably will contain 9.2 firmware at highest (atleast for the earliest batches).