yup, and elon hinted at it in podcast interviews during the past year as well
https://x.com/Loh/status/362036803517169664
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.roic.ai/quote/TSLA/transcripts/2016-year/2-quart...
That the earliest mentions I could quickly find.