I love docs written like this, and writing culture generally. But I've also seen something like this backfire a bit.

I think this approach is particularly good for docs where the assumption is the audience wants to understand why you reached the conclusions you came to, and the doc is sort of a persuasive argument. I think this is a valuable doc (and how I like writing and reading), but it is not always the case.

I think often you do want to start with the conclusion, the "end" so to speak, to orient the reader. And also to address the reader who trusts your judgement, and just wants to get up to speed. I've seen a lot of cases where the audience might not be ready/want to follow along w/ a train of reasoning, they want to know the punchline. And once they do, then they might want to follow up.

Nothing wrong with sticking a summary up top, and then laying out the arguments below.