World Beyond episode 4, "The Wrong End of a Telescope", ends with a post-credits scene that teases big things for The Walking Dead universe. As a two-season series, World Beyond's story is quite limited, but its potential for universe-altering developments and franchise connections is endless. Much of that has to do with the Civic Republic (once known as the helicopter group) and, of course, Rick Grimes, who was taken by the Civic Republic Military in The Walking Dead season 9 and hasn't been seen since.
While there's a lot more at play in World Beyond's story, the crux so far has been about Hope and Iris Bennett searching for their father, who had left the Campus Colony to work with the Civic Republic's science team to potentially find a cure for the zombie virus. Everything seemed to be going fine, but Hope and Iris found out that their father was in danger, and so, they left the community to find him themselves and bring him home. Viewers got a bit more of that backstory in World Beyond episode 4, but the biggest piece of information came at the end of the episode.
The World Beyond episode 4 post-credits scene takes place at an unspecified time, but it's clearly at the facility where Dr. Leo Bennett went to. A photo on the unidentified woman's desk implies that she works on the same team as Dr. Bennett and someone from the Portland community, which doesn't bode well for Leo since one of the zombie test subjects is possibly that Portland scientist. However, unlike them, she appears to be from the Civic Republic, hence the three-rings tattoo on her right hand. The scene confirms the Civic Republic is studying the zombies; the test subject A.4.0.2 (Dr. Samuel Abbot from Portland) recently reanimated and was given psychological stimuli, which he didn't react to. And now he's scheduled to be tested against climate variations.
Judging by the numerous recently-reanimated zombies in the facility, the Civic Republic has pushed a lot into this initiative, which is why they brought in scientists from other communities. But what's interesting is that the post-credits scene ends with the camera focusing on the photo of the four scientists, including Leo Bennet. At the same time, the woman has another test subject brought out when she was done with Abbot, A.4.0.3, which could imply that the next zombie is also someone from that group. But even more interesting is that this could provide some insight into a long-running question from the main Walking Dead series: What do the A and B designations mean?
For years now, The Walking Dead has toyed with the A and B names, which have been associated with the Civic Republic. There have been some explanations during that time, but now, World Beyond has provided viewers with a proper meaning. A appears to mean test subjects - specifically, people who recently died - while Rick Grimes was B, possibly someone who can work in the Civic Republic Military.
This is evident given the two test subjects were recently-reanimated zombies, and the designation for Dr. Abbot was TS:A.4.0.2.; "TS" stands for Test Subject and "A" could imply the designation, with "4" being the group and "0.2" being the number in that group. Plus, the prevailing theory that A and B refer to leaders and followers seems out of place since that's not something that can be determined so quickly. Furthermore, the new A and B explanation ties into the fact that, on the main show, Jadis tried to kill Gabriel whom she marked as an A - falling in line with new zombies. She planned to trade him with the Civic Republic, who appear to need recently-turned zombies, but instead had a B.