Testing is so difficult to read anything into. Look at last year, Sauber were really fast, yet look what happened in the first half of the season. They were slow and unreliable.
I’m afraid no-one can watch the testing! You’d have to go to it to see it.
As for Ferrari they are just testing out the new parts of the car with some old variants they understand such as the front wing.
The only thing that interests me about testing is how the drivers feel the car is coming along, and even then, they might not be telling the truth. I also enjoy seeing all the new shiny cars for the first time!