Well, here is an official
Subaru press release. While they do not directly link the chassis changes to Rally, they certinaly follow closely on their heels..
And a more current
article specifically uses the words "Competition-Bred Chassis" followed by: "A super-stiff Ring Frame Reinforced body structure...". That tells me that at least some portion of the chassis design is related to Rally...
While I agree safety was a large part of the change, I find it hard to believe they did did not include performance and handling as criteria in their design.
Where is Austin when we need him? Torsional rigidity is almost a good thing in a sprung chassis.