I have no clue. I devoted several hours of research today to trying to get a feel for what Elon has planned. Nobody knows, and I have very little confidence in my own guesses.
For what it's worth, I think Elon might be taking the company private. He'd be in a lot of trouble for trying that because of his non-public tweet last week, and this sudden, atypical pre-release of quarterly data and the now very official media advisory for investors and the press feels like a legal effort to walk back liability before Elon actually acts. Haven't heard back from any lawyers as to whether that theory holds any water, which is only one of the reasons I have little confidence in it.
But it feels sorta right, and it would apply whether he takes the company entirely private or was somehow engineering a multi-hundred million dollar capital injection. Merely exercising his options for that purpose doesn't seem to give Tesla enough capital to do anything special, and suffers from the fact that it would make Elon substantially richer, which seems self serving in the context of "putting my money where my mouth is."
If he is going to inject capital into Tesla and increase his ownership share, why not just go big and take it private? He has mentioned a desire for putting Tesla into a holding company with SpaceX so he can move resources back and forth. Tesla probably needs $400-$700m to develop GenIII, and Elon is getting far enough up the billionaire ladder that he might just feel more comfortable writing a check than having to go to Goldman Sachs for it.
SpaceX just got valued at $6 billion a few weeks ago and only looks to get more valuable. Solar City is up big along with Tesla. That puts Elon's net worth somewhere north of $5 billion.
American Express would probably just let Elon put Tesla on his card at this point