I was reading a friend's blog recently, and he happened to note that there was a Star Trek book published in 2017 called Section 31 - Control. Now, anyone who's watched the second season of Star Trek: Discovery will quickly recognize the terms "Section 31" and "Control," especially in connection with each other. I haven't read Star Trek books in years (I've read Star Trek comics more recently; IDW has done a lot of interesting things with the franchise), so hadn't really caught on to the existence of the book and Discovery's apparent wholesale appropriation of it until pointed out. (It's worth noting that the creators of the show have links to the books, which I realize is not entirely unique but has seldom resulted in links between screen and book material.)
Readers of the books, assuming they're interested in new screen material (it was my impression that there was a diminished overlay at the very least in previous years), no doubt made the immediate connection. Readers of Section 31 - Control itself might have had very strong opinions about Discovery's second season, or they might have been perfectly fine with it. You can find a summary of the book here. As far as I can tell, without having read the book myself (although I'd now really love to), there seems to be plenty of room for Discovery's arc to have had the book directly in mind, either as an homage or prequel material.
Discovery has been blazing its own path in franchise lore. Plenty of fans already thought the Abrams movies set a different, more action-oriented standard (#notmyStarTrek). I mention in my reviews how when the series tries to be traditionally Star Trek is when it is least effective. Yet the heart is always there, the yearning for human potential and the inherent belief that the potential is positive, and that's what really matters, that we're capable, a whole crew at a time, of miracles. There's never been a movie or a TV series in this thing that believed genius was held in a single person, but rather than there was a spectrum of extraordinary abilities working in concert.
What Section 31 has suggested since it first popped up in Star Trek: Deep Space Nine was the antithesis of that idea, that genius is to be coveted, protected, exploited. (You can see examples of Starfleet's fallibility outside of the shadowy organization, for instance, with Admiral Dougherty evaluating Data's fate without affection in Star Trek: Insurrection.) It's not just a metaphor about the spy world, but everything that can go wrong when you begin to doubt, lose the ideals Gene Roddenberry championed, believed in, at precisely the point in history when they no longer seemed possible.
Section 31 - Control, the book, is a culmination of Julian Bashir's efforts to defeat Section 31. The Control in Discovery is the beginning of Section 31 losing its way. Section 31 at this moment in history could recruit morally questionable figures like Mirror Georgiou, but it could also win the loyalty of fundamentally good people like Ash Tyler. Tellingly, Control targeted a rank-and-file agent like Leland. Section 31 was featured in Star Trek: Enterprise as well, a hundred years prior to the events of Discovery, and even then it was looked upon as a heinous concept, and yet it seems to have been pushed however grudgingly into a less covert existence, for a time. (Of course, in Star Trek Into Darkness, Section 31 seems chiefly interested in warmongering.)
There's a Georgiou Section 31 series on the horizon. I find that an increasingly intriguing concept.