Post above is a bit vague, but Sainz's full comments paint a clearer picture to my own question (not so much about why they didn't bring upgrades):
All the circuits we have completed since Monza have confirmed that the improvements we made are working to some extent.
I have always said that until we go to Austin to test them on a "normal" circuit, we won't be able to evaluate the improvements we made at Zandvoort or Spa, the circuits where we had the most difficulties. I think this will be the most important test for us to understand how well these updates are working in the right direction, even on a more traditional circuit like this one.
We have nothing new here, we brought this update to Monza, then the front wing to Singapore. We need confirmation to know if the improvement in our pace is due to the circuits at Monza, Singapore, and Baku, or if the updates also have an effect on more traditional circuits like Austin. This is the ideal circuit to give us answers.
It must be said that others have used these three weeks to bring new things, we haven't been idle but have worked in different areas. It seems to me that some teams are bringing significant updates, and that could change the hierarchy a bit, so we will need to reassess the situation.
The next three races will largely determine our chances of winning the Constructors' Championship. If we perform as we did in the previous races, we can believe that we can do it, but if, on these more traditional circuits, we fall even further behind and can't go fast, then our hope will diminish. It’s about whether, when returning to circuits with long, fast corners, we can continue to fight at the top.
https://x.com/FerrariF1FRA/status/18470 ... CVjXA&s=19
