By the time Rick Grimes flew away in a helicopter with Jadis, the rest of the survivors from Alexandria, Hilltop, and Kingdom thought him dead in the bridge's explosion. As the show goes on, certain characters will have held out hope for Rick's survival due to the lack of a body, but one has more information than the rest regarding Rick's fate.
While some fans are seeing it as a plot hole, the fact that Father Gabriel is aware of Jadis having traded people to another community could be crucial. It is unclear whether or not Gabriel communicated this fact to others but he has clearly held onto it. In Episode 9x06, Father Gabriel was seen working on a radio and explaining to Rosita that he believes other communities could be out there somewhere. This is clearly inspired by his knowledge of Jadis and her people which the group had never encountered.
In the moment, the scene with Gabriel and the radio was easy to chalk up as a reference to the comics in which Eugene uses a similar looking radio to make first communication with the Commonwealth community in Ohio. However, the Commonwealth may have already arrived in the form of Georgie. If Gabriel and Eugene are going to open a line of communication with someone new, it's possible they could find themselves connected to wherever Rick Grimes landed.
As AMC sets the stage for a trilogy of films starring Andrew Lincoln as Rick Grimes, it's not unlikely these stories take place during the six years which have passed for the survivors on The Walking Dead. Could they ultimately lead up to radio communication from Gabriel or Eugene bringing Rick back to his family? If this is the case, the first connections to Rick's whereabouts in those films could be revealed on the TV series before coming full circle in the movies.
Either way, Father Gabriel has crucial knowledge about other communities and where Rick Went (though he may be completely unaware of the latter bit) and could play a key role in bringing him back around.
The Walking Dead airs Sundays at 9 pm ET. Fear the Walking Dead will return for its fifth season in 2019. For complete coverage and insider info all year long, follow @BrandonDavisBD on Twitter and watch ComicBook.com's After The Dead each Sunday night following new episodes.