Tesla connect all their products, i would be super suprised if they pump out solar systems that arent internet connected.
they have allowed local interrogation in their previous products, they are likely to do the same with solar as they need them to play nicely and optimally together.
its much better to grab solar / power data locally for fast responsive power control. getting it from the tesla API would be too slow to offer granular control.
for example - you can interrogate the powerwall gateway for production import and export.
with this detail the amount of solar you’re producing (from a control standpoint) is essentially irrelevant.
the only important metric is import / export and how much.
you can rattle the json output with RESTful sensor or use the powerwall integration.