YMMV / Star Trek: Picard S3E03 "Seventeen Seconds"

• Unexpected Character: The return of the Founders (or at least rogue Founders). While showrunner Terry Matalas had previously stated the Dominion War's aftermath and legacy were important to the final season, the Changelings are still first and foremost the Big Bad of Deep Space Nine and Sisko (to say nothing of the absence of overt references to TNG's first spinoff in the preceding seasons of Picard). So, few people (if any) were actually expecting to see the Dominion (or at least a renegade faction of the Gamma Quadrant empire) pop up to antagonize Jean-Luc and the Next Generation characters (let alone a Voyager character in the form of Seven) for the first time in the onscreen canon.