I fear this change will have some unintended consequences: 1. In a Ask/Show HN post, (which is often similar to a reddit AMA), the OP will not be able to reply to clarifications questions until their previous one is 'endorsed'. 2. Multiple ( 2a. Either moderators endorsing multiple such comments, due to race conditions and stale views during moderation, or 2b. Moderators would endorse the first (or "best") of them, a…
What's more, since people with under 1000 karma can't fully participate because unlike high-karma users they can't see if their comment duplicates someone else's and will get stuck in limbo as a result, it's going to be rather difficult for them to reach the 1000 karma threshold - certainly more difficult than it is now.
Then again, if their comment does become approved, it will be more visible than under the current system (less noise) and therefore likely to receive more upvotes. Also, their bad comments won't be punished with downvotes.