It would be hard to pick two automotive markets more different than the ones the C8 and Raptor occupy. I just don't think there is much if any linkage here in terms of the low price on the C8 somehow embarrassing or shaming other brands to lower their prices unless they have to directly compete with the C8 in the under $100k sports car segment.
I have had a number of Corvettes and Porsche's and enjoyed both, but high performance numbers at a low price usually isn't the only factor in a buying decision even for a sports car. Other things like build quality, driving and ownership experience are factors too. Still my hat is off to GM for bringing what promises to be near super car performance for a shockingly low price.
Finally C8's will probably have ADM attached for all of 2020 or longer until production ramps up. So if short supply and ADM makes it a $80-$90k car, the market will have made it's own judgement in the upwards direction making it easier on the competition initially.