Glad to hear they're finally going to address Fusco being out of the loop. There were some odd moments in season 4, where Fusco was right in the middle of the fight against Samaritan, but it was never explained how much he actually knew about what was happening or why. They pretty much ignored the question in "If-Then-Else," and they brushed it off in "Control-Alt-Delete" with a joke where Harold gave a long explanation about what he was doing on the computer to counter Samaritan and Fusco just said "Were you talking to me?" Not to mention the Machine's-eye-view shots. As we saw with Saul Rubinek's character and with Carter, the Machine uses yellow squares to identify people who are in the loop about her existence and white squares for people who don't know about her. (At least, since her reboot after season 2. Before, she used yellow squares for the "irrelevant" team and blue for the "relevant" agents like Shaw, but from season 3 onward, she used yellow for everyone in the know, including Control and Hersh.) And yet Lionel's square has remained white, meaning that he's still unaware of the Machine. So they've been going with this status quo where Fusco is hearing the others talk about Samaritan and computers and stuff and doesn't seem at all curious about what it all means, which is weird. You'd think that lack of inquisitiveness is a poor trait in a detective. And just what does he think "Samaritan" is? Some kind of evil corporation? Another hacker like Harold? What goes on in his head? So keeping Fusco out of the loop has been very artificial, and I'm glad to hear they're actually going to deal with that issue.
The talk about bringing back characters is interesting. One thing I got to wondering about in my rewatch is whether we'll ever get followup on certain characters that were introduced and then faded away. Zoe Morgan was AWOL for a while but came back a couple of times in season 4; hopefully she'll get at least a swan song appearance in season 5. Then there's Leon from season 2. He was a major player in that season -- the first person that ever got to use Finch's computers other than Finch himself -- but then he totally disappeared without explanation. (The other day I saw a picture of Ken Leung in The Force Awakens and thought, "Hey, it's Leon! That's where he went!")
Then there were a couple of one-shot episodes introducing evil masterminds who were set up as potentially recurring, but then never heard from again. There was Julian Sands as the intelligence agent who blackmailed the doctor in "Critical," and the mysterious, unidentified phone voice who blackmailed the 911 operator in "Last Call." Both threads that were completely dropped. (I wonder if the mysterious voice was originally meant to be Sands's character but he was unavailable. They were both blackmailing good people to do horrible things for them.) I can understand that the Samaritan arc took precedence, but I would've liked a bit of closure on those. (Even if it's just to establish that they both fell victim to "the Correction.")
I also hope Annie Ilonzeh's Harper from season 4 returns. It seemed the Machine was cultivating her as an unknowing asset, and I'd like to know where that was leading. (Plus, she's hot.)