I don’t think those passages grant unilateral authority in all ways.
I realize you do. But I disagree. And I think that’s precisely why they wrote the rules that way.
So here...
DMG page 4: "And as a referee,
the DM interprets the rules and
decides when to abide by them and when to change them."
DMG page 4: "The D&D rules help you and the other players have a good time, but the rules aren't in charge.
You're the DM, and you are in charge of the game."
DMG page 9: : "The
rules of the game are based on the following core assumptions about the game world." and "
IT'S YOUR WORLD - In creating your campaign world, it helps to
start with the core assumptions and consider how your setting might change them."
This is about naming, but the idea is still there.
DMG page 36: "
It's a good idea to establish some ground rules with your players at the start of a new campaign."
DMG page 59: "Each plane's description includes one or more optional rules
that you can use to help make the adventurers' experiences on that plane memorable."
DMG page 235: "
The rules serve you, not vice versa. There are the rules of the game, and there are table rules for how the game is played."
DMG page 235: "For instance,
players need to know what happens when one of them misses a session. They need to know whether to bring
miniatures,
any special rules you've decided to use..."
DMG page 235: "This section gives recommendations for
table rules you can establish to help meet that goal."
DMG page 235: "
You might need to set a policy on rules discussions at the table."
DMG page 237: "Remember that
dice don't run your game-you do. Dice are like rules."
DMG page 263:
AS THE DUNGEON MASTER,
YOU AREN'T LIMITED by the rules in the Player 's Handbook, the guidelines in this book, or the selection of monsters in the Monster Manual. You can let your imagination run wild."
DMG page 263: "
Before you add a new rule to your campaign,
ask yourself two questions: • Will the rule improve the game? • Will my players like it?"
There are 12(not an exhaustive list) instances where the rules tell the DM to decide on the rules and rules changes. Hell, that last one from page 263 tell the DM to consider the players, but there's no actual requirement for the DM to do so.
The following are two more passages granting the DM sole authority, but do like the one on page 263 suggest, but don't require, that the DM talk to the players.
DMG 34: "
Feel free to change or ignore rules to fit the players' roleplaying needs, using the advice presented in part 3 of this book."
DMG page 34: "What's the right way to run a campaign?
That depends on your play style and the motivations of your players. Consider your players' tastes, your strengths as a DM, table rules (discussed in part 3), and
the type of game you want to run. Describe to the players how you envision the game experience and let them give you input. The game is theirs, too. Lay that groundwork early, so your players can make informed choices and
help you maintain the type of game you want to run."
That last one there is the strongest in your favor, but even then it doesn't limit the DM's authority or require him to do those things. It just voices the obvious(which I strongly agree with) that the DM should take the players and their desires into consideration when altering rules.
So I've provided more than a dozen examples of the DM having total authority over the rules and any changes. Can you provide even a single instance where the game says that the players have ANY authority to change the rules or stop the DM from making changes? Even one?
My interpretation is based on more than a dozen passages that say what I am telling you. What is yours based on other than just how you want it to be?