Companies can cancel your vested equity for any reason. Read your employment contract carefully. For example, most RSU grants have a 7 year expiration. Even for shares that are vested, regardless of whether you leave the company or not, if 7 years have elapsed since they were granted, they are now worthless.
Once vested, RSUs are the same as regular stock purchased through the market. The company cannot claw them back, nor do they "expire".
> same as regular stock purchased through the market
You cannot purchase stock of a private company on the open market.
> The company cannot claw them back
The company cannot "claw back" a vested RSU but they can cancel it.
> nor do they "expire".
Yes, they absolutely do expire. Read your employment contract and equity grant agreement carefully.
Right. In the case of OpenAI, their equity grant contracts likely have a non-disparagement clause that allows them to cancel vested shares. Whether or not you think that is a "valid reason" is largely independent of the legal framework governing RSU release.
But none of this means the company can just cancel your RSUs unless you agreed to them being cancelled for specific reason in your equity agreement. I have worked at several big pre-IPO companies that had big exits. I made sure there were no clawback clauses in the equity contract before accepting the offers.