Updated first post from more sightings and checking of in-store scanners.

It looks like all of the stores getting these in, now have them, except BigW, which have the Deluxe and Voyager Siege toys in their systems, but aren't yet out in stores yet.
Leader Class Siege is going to be difficult to obtain here though, as Kmart and BigW still don't have it in their systems, while Target is still unknown (the in-store scanner wouldn't read the image on my phone, so I have to go back with an empty toy box).

Items still not listed, and probably not expected there by now...

BigW
Botbots 8-pack
WFCS Leader

Kmart
Botbots 5-pack
WFCS Leader

Target
Botbots 1-pack
Botbots 8-pack
WFCS BattleM
WFCS Leader (unknown)