I can't see it myself even though I have no experience of the car model.

Lots of the vehicle content is Vauxhall/Opel/GM (I think) suitably modified by Saab.
It doesn't sound logical that a dodgy cruise control switch would cause reduced performance. A reduced performance condition is usually caused by something that affects tailpipe emissions or something affecting engine integrity or reliability.

I heard on the grapevine some Vauxhall models have reduced performance simply because they are overdue for some maintenance and once the service indicator has been reset they are fine again. I don't know how true this is. I know of one Vauxhall that flags up an overboost fault and cuts performance when there is an egr valve fault. The true cause could not be discovered by a generic obd scanner and it was only when it was plugged into something with some very expensive dedicated software that it became obvious.

There is no telling what the Saab boffins have done to the management programmes. There are vehicles around that go into reduced performance if the oil level or pressure is low and maybe they thought that might be a good idea.

I suggest you continue your Saab research at the local Saab dealer or on one of the specialised forums, but certainly I suggest you get the code re-read by a dedicated diagnostic machine.