I'd never heard of this. It turns out it is very rare for publicly traded companies [1]. In these cases, I would guess it comes down to contract terms. But again, it's not as though the law would compel an individual to continue working at a company. It would just come down to what the contracts say, and, potentially, how the courts interpret those contracts in the event of a lawsuit.

[1] Examples I found: Worksport Ltd., Exicure, Inc., Rainmaker Worldwide Inc., and Acorn Energy, Inc.