Making a stupid but legal decision is not valid grounds for a lawsuit of that nature, though. All the board has to do is demonstrate that their actions were taken in the good faith belief that it was in the corporation’s best interest and that no deliberately false statements or fraud was committed and the lawsuit goes away.
This Bud Light matter might be a viable case if it could be established that AB-InBev's actions were a violation of fiduciary responsibility by putting management's political agenda ahead of the interests of the shareholders and in doing so created a significant loss in share value...particularly if it can be established that the board was being pressured by certain institutional investors (like BlackRock) to do so.
Of course, from a practical POV, the judge hearing his matter would be a problem if he were politically biased toward the Left...