I think you are asserting misinformation. If Gebru did not list a resignation date and made the resignation conditional on demands in her ultimatum, then the resignation would be effective instantly under the conditions of not fulfilling her ultimatum, just as she said.
You would need example case law of employees declaring a resignation conditional not on any date or time, but on specific demands which are immediately denied by the employer.
>> If you don’t give me a raise then consider me resigned.
>> I don’t give you a raise, therefore I accept your instantaneous resignation.
This linked example where an employee listed a departing date and then was terminated sooner than that does not seen applicable to Gebru’s situation, and I don’t appreciate you saying my comment is misinformation if this is the level of countering material you’re providing. I’m happy to be shown to be wrong, but that’s not what your link describes at all.