What does Prey have to do with System Shock 2? Why would Zenimax make a spiritual successor to it?
Why not? After they scrapped Human Head's version for whatever reason, they had to come up with something new. A Shock inspired sequel is probably closer to Prey 1 than the bounty hunter thing.
And it's not like the games would somehow become connected, they're just drawing inspiration from another IP in terms of gameplay and overall feel. The silly names in the concept docs are just there for reference. At least I hope they are just that.
It's totally going to be a prequel to System Shock, retconning Shodan into a former human rights activist.