Telltale’s Tales from the Borderlands did an excellent job re-purposing Gearbox’s world and characters in an entirely new context. It turns out the developers behind the narrative adventure hoped (and still hope) that Gearbox might, in return, do the same with the characters they created.
In an excellent oral history of the series in the Campo Santo Quarterly, various members of the team behind the spin-off cover the fact that main characters Rhys and Fiona were designed to be reused in the main shooter series.
"The hope was," explained producer Adam Sarasohn, "with Fiona, with Rhys, we wanted to essentially hand back to Gearbox fully-fleshed out, heroic characters that they could then use in Borderlands 3 and beyond."
Source: IGN PC Articles