Not sure if his latest call is to buy more time, but to say that it is his only motive is just wrong. Musk has always voiced concern about AI, even if he pushes for it at the same time. This is from 2017 when OpenAI was still in his plan:

https://www.cnbc.com/2017/09/04/elon-musk-says-global-race-f...

> “Last month he co-signed a letter with other leaders in robotics including Google Deep Mind’s Mustafa Suleyman, calling on the United Nations to ban killer robots”