It wouldn't be the first such configuration from Stuttgart, although it seems likely to be smaller than the old 924/944 lineup. The magazine is reporting that the new car will use a flat 6 from the Boxster/ Cayman with all-wheel drive on a VW platform. That engine choice would preclude the Golf platform since the boxer engine wouldn't fit in the transverse engine layout. So if this comes to pass, a variation of the Audi A4 architecture is likely to underpin the new model.
Another more likely option might be to use the Golf platform with a variation of the the R32 drivetrain. This would certainly provide the necessary performance and it wouldn't be out of line with what Porsche did with the Cayenne. MotorAuthority has a rendering of what such a car might look like, and it's definitely better than what we've seen recently in spy photos of the Panamera. This car would definitely be a lot closer in spirit to what a Porsche should be.