Porsche isn’t ruling out giving the 911 GTS hybrid a manual gearbox. For now, it is exclusively available with an eight-speed PDK.
Porsche’s T-Hybrid system is pretty complex, making the current setup incompatible with a traditional manual. Porsche Cars North America CEO Timo Resch says that could eventually change.

“So, the technology setup that we have in place right now and a manual transmission… they are not compatible. That’s something that we see right now. But at the same time, it’s great to have an engineering team in Weissach that never stops thinking and has a lot of great ideas.”

Porsche also appears determined to keep manuals alive elsewhere in its range. “You can be assured that we will try to offer manual transmissions as long as we are legally allowed to and as long as there’s customer demand, and we see customer demand for the optional manual transmission also lasting well into the next decade.”
Source: The Drive
Anyone wondering why Porsche would do this. This is a result of left wing European mandates which force car companies that produce above a certain quantity into forced compliance for emission control. They face large fines if they exceed their designated threshold. To avoid this they must produce lower emission vehicles. It’s the exact reason why Ferrari is forced to build an EV.