It's been discussed for at least a decade. A Wall St analyst even wrote a note suggesting it back in 2017 that was widely covered in the media. Most people think is very likely to happen eventually.
A Wall St analyst was asking questions about it on Tesla earnings calls in 2016 and later wrote a research note about the idea. Been widely discussed since.
https://www.cnbc.com/2017/12/05/the-case-for-elon-musk-to-co...