It sounds like you don't even know what the API changes effect, and why they are bad for both users and moderators.
Mods were promised first party moderation tools years ago that still do not exist. API changes are killing third party alternatives without providing a replacement. https://www.reddit.com/r/modnews/comments/141oqn8/comment/jn1234u/
The Official Reddit App on Android has issues banning people that have already been shadow banned by reddit. https://www.reddit.com/r/modhelp/comments/13t1npy/cannot_ban_a_user_in_my_subreddit/jlsupdm
There is poor accessibility support for visually impaired users. (r/blind is in the top 5% of subs and they can't bother making their app accessable for them, does Reddit really care about its user base?) https://www.reddit.com/r/Blind/comments/13zr8h2/reddits_recently_announced_api_changes_and_the/ There are even a couple posts on r/warframe from blind users
If Reddit actually cared about selling API access to 3rd party Developers, it would not have taken 3 months to respond to a developer. Honestly can't believe they claim to be "profit driven" when they can't be bothered to provide access to their PAID API. https://www.reddit.com/r/reddit/comments/145bram/addressing_the_community_about_changes_to_our_api/jnk2q0e
They do not have documentation ready for the new API, even though it should be going live at the end of the month. https://developers.reddit.com/waitlist
Helpful bots like remindme/savevideo/wiki bots/wanderingdwarfminer are dead with the API changes. Can't pay for access to the API to keep them alive and there is no available documentation available to update them either.
Then there is also the issue that unless a moderator is on the first party app/official site, they can not see/moderate any content on a NSFW post. Want to post anything that breaks the subs rules, make it an NSFW post.
There was also some mention that it may be possible in the future for trolls to brigade a sub and take it over. Obvious targets for this would be any subs that are educational (r/learnjapanese already had someone requesting to take over), AskHistorians: push whatever alternate history you believe in, or for the "controversial" subs, I expect politics/lgbt type subs to be harrassed if a policy like this goes forward. Why is this even an option support plans to offer, and pass it off as "being in the community's best interest". If someone doesn't like the moderation team, they should be told to make their own sub, not be given the community the mods worked to create. The sub would have died long ago if mods were doing terrible job.
Just because something doesn't effect you directly doesn't mean it doesn't have negative consequences for the rest of the community or even an unforseen impact to yourself. Without the blackout, a lot of these issues would have gone unnoticed by the general community, these were all points I found skimming through the AMA.
*Feel free to correct me on any of my points, or even add to them. A lot of this information was learned through skimming, and I've linked to some quick sources that I used as references, or even better, go ask the affected communities directly how the API changes effect them.