Basically any items like that - books, data discs etc. offer random free tech when researched. Everyone will learn this rather quickly, no worries.
I think the complaint here is different, although poorly written.
Similar to complaints about dynamite research several months ago.
The issue is that (from player's perspective) you have already researched Pillow Book when you finished the Plotting research. You can manufacture it, so hey, you know everything about it, right?
And since it is not a very appealing manufacturing project, 99% of the people will never manufacture it, because they see no point in it.
And thus they will also never start researching it "again".
It makes (some) sense when you know the tech tree and once you get explanation from the author... but for new players, this is beyond confusing.
PS: speaking from my own experience... if I had not looked at the research tree in the techtreeviewer on the web... I would also never manufacture a pillow book... and would be cut off from critical research path until year 2608 when I would run out of things to research and research pillow book as last.... if I even bothered to build it in the first place, which I think I wouldn't... so effectively I would be stuck forever.