The Nexus-9 are the first Replicant model of bioengineered humans created by the Wallace Corporation, which continued Replicant manufacturing and commerce after acquiring the rights from the bankrupt Tyrell Corporation in 2028.
The production of Nexus-9 began in mid 2030s. This information is known from the Blackout: 2022 anime short were it is stated that, following "The Blackout", "It took over a decade for THE WALLACE CORP. to win approval to manufacture a new breed of Replicants".
Fate of the Nexus-8 Relicants
The Tyrell Corporation was responsible for the creation, manufacturing, and selling of replicant technology since the earliest Nexus models were produced. In 2019, a rogue Nexus-6 replicant named Roy Batty killed the head of the corporation, Eldon Tyrell. This caused the next variant, the Nexus-8, to be rushed onto the market in 2020.
Nexus-8 replicants had open-ended, natural lifespans and were used for Off-world warfare and tasks humans did not want to do on Earth. Anti-replicant sentiment led to Human Supremacist movements and, with the use of the Replicant Registration Database, murder of replicants became a regular occurrence. This culminated in the Blackout of 2022, allowing Nexus-8 replicants to blend in with society, followed shortly by the outlawing of replicant technology and the designated retirement of all Nexus-8 models.
This also sent the Tyrell Corporation into bankruptcy, allowing Niander Wallace to acquire it in 2028.
2023: Beginning of the Replicant Prohibition
In 2023, the governing magistrates legislate an indefinite "prohibition" on replicant production by the Tyrell Corporation. This lead to the decommissioning of the Nexus-6 Replicant models, as well as the Nexus-8 Replicant model. Unlike the Nexus-6 which may not live past its programmed 4-years lifespan, the Nexus-8 is characterized by a natural, indefinite lifespan. As a result, the support of Blade Runner units is request to "retire" hidden Nexus-8 Replicant models.
2036: End of Replicant Prohibition
Replicant technology was prohibited after the Blackout, regarding any restrictions that Tyrell had placed into all of their models as negligible and useless after the Nexus series proved to be rebellious. Wallace, after acquiring the Tyrell Corporation for his own use, developed in secret new replicants that would obey. These would be the Nexus-9, and in 2036 Wallace demonstrated their obedience in front of the magistrates of Los Angeles. This overturned the prohibition and allowed replicants back into the workforce and society.
The Nexus-9 series is primarily known for its' obedience. While retaining the ocular implant from the Nexus-8, Wallace made the Nexus-9 series to live as long or as short as a customer would want, and demonstrated their obedience by ordering an unnamed Nexus-9 to choose between his own life or that of Wallace's. The end result was the replicant cutting his own throat.