Yeah, some of it felt very last-minute trying to make everything fit with CeCe, like revealing that oh yes she had dated Jason her brother, but don't worry they definitely never actually slept together! Or that oh yes CeCe's friend Bethany killed Toby's Mom when she was just a girl and CeCe's mother covered it up after she was framed for it, even though that doesn't at all fit with the timeline of Toby being a teenager when his mother died. I just don't buy that they planned CeCe out as A since season 3, it seemed more like season 5 was where they started laying the groundwork for 'Charles', and then they throw in a bunch of exposition this episode to try and make everything from season 3 fit with CeCe as A

And I agree that Sara seemed very obviously shady from the beginning, but it was again very underwhelming to then throw out that she was Black Widow, that she was Red Coat. I wanted it to be someone really surprising y'know, and also someone that made sense for the writers to be picturing as Black Widow when they were writing those scenes. Instead they didn't even give us a motive for Sara working against the girls, and those are the kind of twists that I was really looking forward to seeing. The pieces just didn't fall into place for me, so much as it felt like the writers were straining to go back and make all the pieces fit