Profit is a lot harder than cashflow. For a long time, Tesla has been plowing money into CapEx; that comes back as depreciation, which reduces profit, but not cashflow.
With all the cars in transit at the end of Q1 (and there will be cars in transit), it's going to amount to a substantial drop in deliveries versus Q4 (though not a drop in production) -- add in one-time items and, to analysts like me, has seemed unlikely to be much better than break even. The transit time is just too high: 18 days Fremont to Shanghai is great, but it's significant.
S & P 500 inclusion after 19Q2 as opposed to after 19Q3 would benefit Tesla's investors.
Would it benefit Tesla itself?
Because in principle, Tesla could focus on North American deliveries during March and in that manner keep their number of vehicles in transit low at the quarters' end.
They would then have the option to transition to exporting a more constant fraction of their production on a monthly basis at a later stage (after S&P 500 inclusion), at which point they would incur the one-time hit of a quarter with a high number of vehicles in transit.
But if this would not benefit Tesla itself, then they might as well go for the longer term advantage of exporting a more constant fraction of their production on a monthly basis from now on.