Statement on the Purpose of a Corporation

No, they can't. If management took an action that is within their power to take it cannot be reversed at shareholder whim. They can certainly throw out the current management and install new management who will attempt to reverse what the old management did, but what is done is done.

Here are the words I saw:

value, customers, expectations, investing, employees, compensating, fairly, providing, important, benefits, supporting, training, education, skills, changing, diversity, inclusion, dignity, respect, dealing, ethically, suppliers, good, partners, companies, missions, communities, respect, protect, environment, embracing, sustainable, businesses, generating, long-term, shareholders, capital, innovate, transparent, effective, engagement

Why?

1. Look at how the gig economy pushes contractors further and further towards being employees in all but name, but so much in the way of benefits is tied up in whether or not the name or classification applies.

2. The statements talk about benefits that corporations bring and the support they provide but neglect to mention the costs they incur and the side-effects they place upon others. Corporations are organisms of a kind, and most if not all organisms consume some inputs to produce some outputs. Some of the those outputs are waste. That waste must to be accounted for and processed. Where would the BP oil spill and the PG&E wildfires be accounted for in those statements.

3. The statements avoid the mention of the term consumers, which is how many companies perceive and treat their customers driving the interactions between them to be increasingly banal and scripted. Consider how often in this forum we hear of "selling eyeballs" in advertising.

4. Similar to 3 but more generally, the statements make no mention of accountability in the cases of the spectrum of harm caused by ignorance, negligence, and further along that spectrum all the way to outright malice. The statements try to separate the positive things that human beings are capable of producing from the negative without mentioning the negative at all never mind the ever present probabilities. Failing to mention and own the harm that a corporation can cause makes me think of "rainbows and unicorns", and results in the corporation failing to truly possess genuine humility.

5. I think all the four points I listed above are actually a direct result of this point that I'm about to expand upon: for whatever reasons, corporations try to remove humanness from within and without. By removing the humanness from within, the corporation becomes less sensitive when it does manage to do harm. By removing the humanness outside, they reduce the other human beings they work with into a number of nouns: customers, employees, suppliers, communities, shareholders.

As a point of interest, consider the US Constitution and how it both defines the frame of the US government and the other entities it interacts, but also sets constraints on its behavior.

I hear this over and over. What statute demands this?

You are using it this way, but I have many times heard terrible corporate behavior dismissed because they were simply following the law that they must maximize shareholder returns.

That's basically all there is to it.