I see this kind of story occasionally, and have to wonder what it means to "discover" something in this sense. Clearly there's some level at which informed people are surprised by a finding, so awareness of this manuscript is new. On the other hand, he basically saw a reference in a book catalogue from the 1920s, so there's some broader definition of "we" and "knew" which includes written records in which we already knew of its existence.
The same could be said about archaeologists discovering a lost city, since it wasn't always "lost" and was certainly discovered many times before. I guess the timescale gives the impression of a "fake discovery".
Yeah, but we're talking a new work by a prolific author with more than 8,000 articles of writing known. An Essay Concerning Human Understanding and reading about the empiricists (berkeley, hume, locke) shook my world as a teenager. The works and letters of his contemporary philosophers and brilliant people made me a better person, giving things a great deal more of critical thinking. I love how in some of this he's saying that if tolerating catholics helps the prince and commonwealth then he's for tolerating catholics. That's ridiculously apt and healthy.