As others have suggested, just because Shakespeare may not have supervised the publication of his sonnets, doesn't mean that he didn't care about the order (when he was circulating the manuscript(s), which he almost certainly did), nor does it mean that the order in the 1609 edition isn't purposeful. As you say, it's speculative.

On the other hand, even if he profited from the sale of the text, he may not have cared about a sequence of poems he almost surely wrote 15 years before. Whatever else we know about Shakespeare, we know he got good value for his work. But it's quite possible to imagine him giving someone the texts and using the money to buy real estate, or whatever, and not worrying about anything more than the next play.

I'll bet Nabokov's posthumous work won't be a aesthetically pleasing book. But I'll also bet it illuminates his practices as a writer--something invaluable to scholars, especially ones who can't get to Switzerland. Wouldn't you love to have Shakespeare's drafts and notes? Or Cervantes's? Even (especially?) if they sucked?