Yes.
Otherwise we would have no proof that the extra material you're adding isn't copyrighted by someone. It's quite common for modern publishers to add introductions or illustrations to a public-domain novel, and we need the same standard of proof for these additions that we do for the main text.
This doesn't apply to an occasional word or two that was omitted by mistake when the text was first typed. For example, you don't need to clear another edition just to restore the words "thus perfected the" and "eliminating all" to the sentence:
And while we Country, we were also sorts of tediums, disputable possibilities, and deadlocks from the game.
while fixing typos.