I am, of course, not saying you are wrong....who knows??? But why are you so sure that Raxxla has been "identifiable and discoverable" since Gamma? Do we have any evidence of this?
There are lots of things that have been "in game" since Gamma, but some we couldn't explore until Horizons and others we wont be able to explore until Oddessy.
Just experience and....
gut instinct!
But I've always thought that DB wouldnt put it into the game without it being accessible from the outset.
I think he plays fair
Not convinced by the conspiracy theories!