Are Orcs reincarnated?

Later words on Orcs: speculations, rather than revisions? Certainly. But I accept later speculations rather than older ones, usually. That's the later known idea of Tolkien's, which logically would replace the older one (if we had record of him finally deciding the original one was the best, I'd go with that).

To explain myself, I should probably give a short summary of my method of cannon. Firstly, anything published in Tolkien's life time on Middle-earth I feel bound by in all but one area, because Tolkien felt bound by anything published in his lifetime as well. The 'one area' are the Appendices, because that was put together in great haste and mistakes have been noted there later: Tolkien accidentally may have omitted a Numenorean King, the extra information about Durin VII was lost, and such things. There are also contradictions. Sam Gamgee, for example, is given two different birth dates.

So what was published in his life time on Middle-earth? The Hobbit, The Lord of the Rings, The Adventures of Tom Bombadil and The Road Goes Ever On.

Secondly, one has all the other stuff to deal with. All the stuff published after Tolkien's death. In these instances (my logic is that a later idea replaces the older one or must be accepted to if we haven't heard the even later idea) I go with the latest known word on the subject, unless this contradicts what was published in Tolkien's life, which he felt bound by. That is, if it does without a doubt contradict a work published in his lifetime, it must be an accident on Tolkien's part (the exception being in a few places of the Appendices) because he felt bound by those.

Ofcourse, there is still a bit more to that. I'm not going to go around calling Maedhros Maedron because Tolkien declared (its published in Peoples of Middle-earth) in his last four years that that was what he was going to change his name to, many people would wonder just who I was talking about (as they ought to be expected to). That's just one example of many. Another example: there are later unpublished texts that differ from the older ones (neither differing from published ones) in which it is impossible to tell whether Tolkien changed his mind or had forgotten what he wrote earlier.

Other people do different things, noone agrees on what is cannon, so I try not to be forceful about ' my cannon', as people apparently put it. I'm just telling you how I arrive at conclusions.

But I think it apparent by 'speculations' Christopher Tolkien meant the speculations of his father - even though it concerned the speculations of his characters (it would thus apply to both his father's speculations and the characters').

I mean, in The Quenta Silmarillion and Of Dwarves and Men (this latter was the original essay in which that bit about the Drugs, Orcs and Men appeared) it is the speculation of the Elves, but in parts of the narrative of the former it is the narrator who says Orcs were corruptions of Elves, and after the speculations of the Elves was stated in one of the passages, there is a narrative note saying 'in which they guessed all too near, tis said'. As Tolkien had said in Letters they were made from Children of Iluvatar, the passages in the Quenta convey to me Tolkien's opinion - put into the heads of Elves. So I think the same of the Drug passage, esp. since there is that line about 'still, some thought~'.

It also may be noted that Tolkien in his persona as translator doesn't 'know' anything about what is true, really, he could only study and base his factual conclusions on the perceptions of persons in histories. In this point of view, The Quenta Silmarillion was put together in Numenore, so the narrative views would probably be attributed to them. But that would be true for any point in this view, and if only the other-than-character-ideas were accepted as true, then we couldn't accept anything as true. You have to draw the line somewhere.

Yet I agree we will never know for sure.