> Does the change mean the most competent solution architect who has successfully designed and implemented many complex systems from scratch is capped in salary package because they're not doing the important job of demanding those around them fill out TPS reports all day?

In house solutions architects are not really a thing at FAANG. Designing and implementing systems is what mid+ level SWEs are expected to do. The solutions architects I have seen were all in the sales org helping external customers better use the cloud. My experience isn't exhaustive of course.