The latest published comments from AP seem to confirm the new Cayman GT4 will indeed be a flat-6 4.0 n/a with a manual gearbox.
Porsche cannot possibly designate this car a 718 if they want to retain credibility with their marketing on the origins of the 718 as a flat-4 powered machine.
They should call it a Cayman GT4 like the previous model.
For my current requirements which is 90% touring, that rules the new GT4 out as dead-in-the water for me. Such a shame, as I didn't get the chance to own the last GT4. A car made in heaven for me 3 years ago. OPC preferential pecking orders excluded my enquiries. I have now moved on.
My interest is now fully focussed on developments of the 718 flat-4 turbo. Provided Porsche don't make the evolution 718 too track-focussed extreme, and offer a PDK option, I will be very interested in considering a possible upgrade from my present 718CS, which is coming up for 2 years old, with 17k miles up and counting.
Early 2019 suits me perfectly for the launch of this new evo 718 Cayman. I consider the 2.5t engine to be the right choice. The current 718 Cayman GTS has 365bhp. Hopefully the evo 718 will at the very least exceed this figure. I don't see a problem with positioning such a car above the 718 GTS in power, but with the emphasis on lightness rather than heated seats and steering wheels etc. Customers can then decide which suits their needs best.
I'll also be interested in the choice of designation for this new model. Traditionally the "T" moniker was for "Touring" on 911 models. I would suggest Porsche designate the new 718 evo as the "R". That would tie-in well with the lightweight, track focussed appeal. My ideal 718 Cayman R would be 2.5t, PDK, lightweight panels, and 375bhp.
Brian