Fridge / Star Trek: Picard S3E05 "Imposters"

• The reveal that Ro Laren is Worf's SI handler re-contextualizes his involvement in the season's narrative. Obviously, Worf's time on Deep Space Nine, his Dominion War-era experience, and his connections with Odo would ensure he'd be involved in the conspiracy investigation regardless. But Ro makes it clear in this episode that she doesn't know whom in Starfleet to trust (a stance probably not helped by her past reputation and not making many friends even before her Maquis defection). But, she did serve alongside Worf during their time together on the Enterprise-D. She knows and trusts him. More, Worf is such an atypical, unique Klingon that any Founder trying to impersonate the Son of Mogh would have a very hard time nailing his "character". So, it makes sense Ro would select Worf as her eyes and ears on the ground.
• With confirmation of a Changeling infiltration of Starfleet Command, it seems strange that neither Picard or Ro would consider the possibility that Janeway herself might've also been replaced (as opposed to just someone on her personal staff blocking Ro's communications). But similarly to Worf's unique personality, replacing Janeway would actually be extremely difficult. Janeway's one of the most prolific officers in contemporary Starfleet thanks to the legacy of the Voyager's odyssey through the Delta Quadrant (and the subsequent Protostar project). With Janeway under that much attention and scrutiny, replacing her and ensuring the Admiral remained "in character" without any slip ups would be extremely difficult and dangerous (especially as the renegades don't have access to Dominion resources this time around compared to the original infiltration campaigns 30 years ago). Compromising a member of her staff instead is the more pragmatic and safer choice.
• At first, it seems strange that Picard and Riker are unaware that Ro Laren — the most infamous member of the Enterprise-D crew and someone who personally betrayed both of them — has been reinstated by Starfleet. But as longtime Trek novelist and reviewer Keith DeCandido pointed out in his episode review, it does make sense internally given the Picard backstory and where Picard and Riker were both at this point in their lives, careers, and the franchise chronology:
  DeCandido: [Picard and Riker] probably were aware that [Ro] had served a second prison sentence (along with all the other Maquis who survived the Jem’Hadar’s massacre), but by the time she would’ve gone through the rehab program she mentioned and was reinstated, a) it was probably after Picard quit Starfleet in a huff, b) it was as part of Starfleet Intelligence, which is one branch of the fleet that probably doesn’t share a lot of info, and c) it might well have been after Riker was dealing with a dying kid.