Then minority’s shareholders will sue because their share value declined and the board’s legal obligation is to pursue shareholder value, not do what the majority owners of company want them to do.
I’m torn on that, but minority’s shareholders have a legitimate expectation their rights should be protected.
I agree that it's not quite as simple as what he was suggesting but it's also not just majority rule, even if the majority want to screw over the rest of the shareholders. That's old established case law, at least in the US. See Dodge v. Ford Motor Co.
They can largely do whatever they want, so long as there is some rational argument that it's for the benefit of the company. If 51% of shareholders in some fossil fuel giant publicly stated that their only goals were to drive the company out of business and screw over the other 49% of shareholders, that wouldn't fly. However it's totally fine for them to push a radical new investment strategy of "buy high, sell low" and drive the business into the ground that way.