With the exception of some short interludes, readers haven't really gotten to see the world around Spensa from anyone else's perspective. That changes with these novellas, as each one is from a fresh POV. The first, Sunreach, centers on FM, while ReDawn follows Alanik, a character readers only briefly met in Starsight, and the final story, Evershore has Jorgen as the main character. Given all of that, you should expect spoilers in this review for the first two books of the series.
Sunreach starts off during the delver attack on Detritus, with FM and the rest of Skyward Flight taking to the sky in the hopes of stopping the unusual attack. When Spensa makes a brief appearance and then, using her strange abilities, leaves again taking the delver with her, FM and the rest of the Defiant Defense Force are left wondering what just happened and what will happen next. The only thing they know for sure is that their would-be jailers aren't the only threat in the universe and if they are going to continue to survive, they need to come up with some new tactics. It's a good thing that Jorgen has just discovered a colony of slugs similar to Spensa's own pet, Doomslug. Given Spensa's recent revelation regarding The Superiority's faster-than-light engines, Jorgen's discovery could be just what the DFF needs to get out from under their oppressor's thumbs once and for all.
In ReDawn, Alanik, an UrDail who was going to Starsight in order to train under The Superiority, has gotten away from the strange colony of humans and returned to her homeworld. Upon arriving on ReDawn, she learns that the political landscape of her people has changed during the weeks she was absent, and it seems the party pushing to have ReDawn join The Superiority as one of its lesser races is gaining ground. As one of ReDawn's few cytonics, Alanik has some political clout of her own, but she is also the only one that is on the side of continued independence. As she struggles to uncover the cause of the sudden changes in her home, she starts to think that the only way she can truly help her people is with some new allies.
While Skyward Flight: The Collection's third novella, Evershore still takes place during Spensa's adventures in Cytonic, unlike the other two, Sanderson and Patterson decided not to publish this one until after Cytonic's release. Given where ReDawn leaves Spensa's friends, and the fact that Evershore is all about Jorgen's reaction to those events and his processing of what happened, it's clear that the co-writers wanted to preserve some shocking events to the reader for when Spensa finished her most recent adventure. In a similar light, I can't really talk a lot about Evershore without spoiling the climactic events of the previous novella. Lets just say that, by the time Spensa joins the rest of Skyward Flight, the very landscape of her people's situation has drastically changed, and it's the events in these three novellas that have led, step-by-step, to this change.
While Skyward Flight: The Collection was marketed as side-stories to the series' main events, I can't see how the fourth book in the Skyward series can't expect readers to have gone through these novellas. The only real way to get around that is to have the other characters debrief Spensa on their busy lives early in Skyward, Book 4, but it would have to be done in a way that appeases both those that haven't read the novellas and those that might eye roll at unnecessary exposition. That being said, Sanderson is a skilled enough writer that I would imagine he could pull off such a recap and please most of his readers.
If you've been following the Skyward series and were waiting for a hardcopy of these novellas before reading them, or if you picked up the ebook or audiobooks individually and want to have them physically on your shelf, then Skyward Flight: The Collection meets that need. Personally, I grabbed the audiobooks as they came out and enjoyed the lead up to Cytonic: Skyward, Book 3's publication, but having the stories printed and bound together makes for a nice addition to a Sanderson fan's bookshelf.
