Nah, the 2.5L engine days are done. The new engine design is much better, only 2.0L, and can do much higher numbers than what Subaru has tuned them for. The power comes on quicker so it's got the same 0-60 as the 2.5L in the STI due to turbo design. the EJ25 has served its time, it is time to retire it.
Also, Subaru STI has already been using the 2.0 DIT engine for the WRX STI in Japan. See the WRX STI S208: https://www.caranddriver.com/news/wing-swap-jdm-subaru-wrx-s...