[lvnfg]

It's a bit messy. Legally the board has to act in the best interest of all shareholders. In actual trials the judges tend to defer to the board's business judgment since they are intimately involved with the company's strategy and operations, unless the opposing shareholders can provide evidence of equal experience or understanding of business. In practice however, sitting on a company's board is a job, and the directors mostly do what the shareholders want to protect their career and professional image.

In this case, Reuters reported here https://www.reuters.com/technology/exclusive-twitter-set-acc... that the deal is subject to shareholders vote before it can be closed.