Legal Question in Business Law in California

First, there is a difference between a shareholder meeting and a board of directors meeting. Sure, there is usually a board meeting held just after the shareholder's meeting, but they are separate meetings with separate notice requirements, etc.

Next, how does the shareholder agreement describe the exercise of the veto power? Is it necessary for the holders of the veto power to be physically present and to exercise the veto power at the board or shareholder meeting? If cleverly drafted, the agreement provision may allow exercise of the veto power retroactively, or a veto might be automatic in the absence of an indication of approval by the holders of the power. Or, the veto power could perhaps be exercised by proxy.

Finally, most such meetings (board and shareholder) require prior notice of major agenda items, per the bylaws. No changes in the board makeup could be made without compliance with all the applicable prior-notice provisions.

In sum, while there may indeed be some easy way for your 65% majority to oust the directors with contracted-in tenure, there can be no certainty that it'll be as simple as taking advantage of their absence from a meeting. It would be necessary for a lawyer with a high degree of familiarity with corporate law to advise after reviewing all the documents (bylaws, the shareholder agreement, etc.)

Seems I already told you this.