Employees and board members don't have the same interests in a BigCo. Sure, board members will judge Zuckerberg on whether he's getting Meta to make progress on the goals he's set in agreement with the board, which should fulfill the board's goals of increasing shareholder value.

But that's not the employee's interest. The employee is interested in whether their employment status is stable, whether their work is engaging / interesting, and whether their employer offers opportunities for advancement, in roughly that order of priority. Employers that focus on that order of priorities typically have no such problems with employee trust.

Zuckerberg might as well have said that he doesn't really care if he has employee trust anymore, because he doesn't foresee , in the short term, Meta employees willingly leaving their jobs in droves in a bad economy, trust or no trust. But smart Meta employees will keep their ears to the ground and their options open. People remember for far longer than economic boom/bust cycles.