I have a both positive views and cynical views.
My positive view is that things have to get better, because they've already hit rock bottom. There are "modern" GSDs that Stephanitz is probably rolling in his grave over. The extremes in both show and sport lines do not reflect the "golden middle" that was sought. The dog that was supposed to be best at nothing, but second best at everything, has become so specialized in the different bloodlines that the breed no longer has the versatility that was desired. So, the pendulum must swing back as people begin to realize that the "real" GSD is becoming more and more rare.
I feel the positive because I have actually seen things change for the better in the past 20 years or so, so it makes me hopeful.
On the cynical side, I think that perhaps technology will be developed that can "sniff" better than a dog can, apprehend a criminal better than a dog can, alert/guard better than a dog can, and help disabled folks better than a dog can. Therefore, the need for true working K9s may be greatly diminished. Police and military, SAR, and other service could find new machines to do the work that dogs used to do. Thus, what is the need to breed the utilitarian traits that we so value in this breed?
If that is the case, then GSDs will have to either change, or die out. 100 years in the future, it may be considered "cruel" and "unnecessary" to make dogs do strenuous or life-threatening work for humans. The only "job" a dog may have is to be a companion and member of the family. As such, aggression would probably be discouraged and you'll see a more placid, retriever-like temperament being promoted.
In which case, hopefully, dogs with confidence, strong nerves and high thresholds will be selected for breeding, and not the shy, reactive, fearful GSDs that we see so many of today. I would rather see a strong-nerved, stable, confident, non-aggressive GSD as a "pet" dog, than a soft and sensitive dog that is easily pushed into avoidance as a means of discouraging aggression. Both types could be okay in pet homes, but I want the GSD to at least be the strong and stalwart type, it if comes down to that.