I'm sorry, I must be missing something. Which companies make up the index funds if (most) CEOs liquidated their companies and invested in index funds? And how would they liquidate at anything close to their valuation without being priced based on their future expectations?
I don’t think they meant it literally. They were responding to the comment that their job was “like” managing a portfolio of investments. And in that respect the strategy of diversifying “like” with an index fund seemingly appealed to the commenter.