Final answer:
The specific black woman who served as interim CEO between 2019 and 2020 and did not officially make the Fortune 500 CEO list has not been named in the information provided. Thasunda Brown Duckett is mentioned as an answer, but her CEO role at TIAA began in 2021, which is outside the mentioned timeframe.
Step-by-step explanation:
The black woman referred to, who served as interim CEO but did not make it to the Fortune 500 CEO list due to the timing of her tenure, is not explicitly named in the provided information. However, since the question mentions Thasunda Brown Duckett, it's important to acknowledge that she is a prominent figure in corporate America and became the CEO of TIAA in 2021, after the timeframe mentioned in the question. It is worth noting that often Black women in corporate America have faced significant challenges in their journey to leadership roles, and their achievements are a testament to their resilience and dedication in a competitive and sometimes exclusive business world.
However, the description provided implies a specific individual who briefly held the CEO position between 2019 and 2020 but does not align with Duckett's known career trajectory. The material cited does not provide additional clarity on this matter. For a clearer understanding of the diversity within Fortune 500 leadership and the roles held by Black women, further research into corporate records or reliable business publications would be necessary.