Comment by mcfunk

It is true that if employers are offering RSUs selectively, the assumption would be that they would offer them to people they wanted to incentivize not to leave the company until after the vesting period at the earliest. However, it offers no guarantee at all that the company would continue to desire the employee's loyalty or that the loyalty goes in the other direction in the first place, since as mentioned the company loses nothing but the employee if the employee is fired or leaves before the vesting period completes.