The Proximate Cause

This (via Reuters):

Twitter has $13 billion in debt after the deal and faces interest payments totaling close to $1.2 billion in the next 12 months. The payments exceed Twitter’s most recently disclosed cash flow, which amounted to $1.1 billion as of the end of June.

https://www.reuters.com/technology/twitter-information-security-chief-kissner-decides-leave-2022-11-10/

The real question is why load it up with debt in the first place. Hubris, overconfident pride combined with arrogance.