Well, Chaos Isaac, if the sales model for Starfinder works anything like Pathfinder, the core book is just a taste of what's there.
They will release splat books based specifically on setting material you're discussing right now. Like they did with all those countries in Golarion, and many of the gods, and even a full setting book. That way, people can choose to follow the canon realeased by Paizo OR just fill the gaps in with their own ideas.
I'd like to point out 40k as something you've specifically used for good setting.
In 1988 I bought Rogue Trader, the first ever edition of what is now 40k. It was a table top game set in a distant future and it had a setting that was barely discussed but hinted at sooooo many things. The God Emperor was a minor footnote in the book. Elder were all pirates, Jokaero were Orangutan space men with the best technology in the galaxy, Tau didn't exist, Tyranids didn't exist (genestealers were just another space alien to be feared) most of the chaos stuff wasn't detailed. However, they had stats for a huge array of monsters and space vampires and other cool sci fi stuff to design adventure based skirmish games around.It's taken 30 years for Warhammer 40 k to reach the setting detail it currently has. Much of that was written in the 90s and has just been rehashed over and over again since then. What's worse, they actually removed a huge amount of the cool species and setting material that existed in the original rogue trader book. Squats being the classic example that people still complain about (suddenly an entire race of space faring combatants are removed from the setting with no reason why.)
Paizo does great settings, which they detail over time but still manage to leave enough mystery that players can create their own spin on things without stepping on creative toes.
Nice going Wrath, you've mentioned the race that shall not be mentioned, which resets the release clock yet again.