I guess people didn't realise because the "hub world" is a set of interconnecting rooms / it own dungeon and not a field.

Also the fact each area is connected to the hub and the others make it feel more distinct.

Their DNA has always been similar, it's just that it is more obvious in 3D.

We kinda did with the Metroid manga.

But I'd definitely like to see in supplementary material how the Luminoth are doing since the end of the event of Metroid Prime 2: Echoes.

I'd said none as they deserve peace,the Luminoth on Aether particularly. Whenever she set foot back on a plane5 in a game bad thing are happening or happened, and planet tend to blow up on her second visit 2 out of 2 (Zebes and SR388).