I noticed that too. I need to check when I get home, but I am pretty sure that the other exclusive items and actual PEs have been made of that composition for a while. I have some non-US Open Premier items and the ones from the past year all have those 3 materials. I do need to double check though.
Some version of Wilson Six One 95. Some cheap Multi.
About to break in a pair of Wimby 9.5s. Rocking the Nike bandana/wristband combo.