The PTAB rejected Mercedes Benz USA's argument, denying the institution and maintaining the filing date of the challenged patent. Mercedes-Benz USA v. Westport Fuel Systems Canada Inc. The petitioner wanted a later priority date to qualify a reference as prior art.
https://www.jdsupra.com/legalnews/provisional-describes-incompressible-1945812/
https://www.jdsupra.com/legalnews/provisional-describes-incompressible-1945812/