Hi Clay,
This isn't quite accurate. The straight scopes have always used normal Porros (no extra prism needed). The angled scopes have used two different designs. The AT used a Porro followed by a semi-pentaprism to angle the light path. That requires two extra reflections, one of them mirror coated because it's below the critical angle for TIR. The ATS and ATM use Schmidt roof prisms.
As for the collapsable scopes, I have an internal view of an AZF 30x75 from 1991 that shows an Abbe-Konig roof prism. Later models use Schmidt-Pechen.
Good to hear that Swarovski, unlike Zeiss, Leica and Nikon, is sticking with Porro for its straight scopes.
Are there any changes to the objective design?
Henry