We don't really know how much, if at all, Elon cares about S&P500. I think he said at one point a year or so ago that it's not a factor or something similar.
However, I'm pretty sure that, once they figured it was possible, the goal for Q1 was to show a profit. Since the $140 million wouldn't be enough to make S&P500 possible already after Q1 anyway it was not that much beneficial to make the profit $156 million compared to the benefit of Q2 also showing a profit. It makes perfect sense saving all of that for Q2.
This makes it $140 million more likely to make a profit in Q2 than if it had been used in Q1. So S&P may matter or not for Tesla but this will help for achieving inclusion. If they are within that $140 million of a profit they will use it for sure. Maybe not for S&P, that would be a nice benefit for stockholders, but for the strength it would show.
The big unknown is how the FCA deal is constructed. Is it solely based on how many credits FCA needs every quarter? Seems unlikely. You don't write a $2 billion deal without minimums included. Is that minimum for each quarter $100 million? $200 million? $300 million?