What are we studying?
You know a lot of this really depends on the individuals reason for studying the martial arts. To say that "newer" forms take away from the art is nonsense. If you are studying the arts from a historical perspective, with an added benefit of learning to defend yourself against a common ordinary thug, the non changing approach is best. There is no need for change.
If you are trying, however, to stay on top of the art of "combat", then I believe your approach would have to include change. Let me say that many "traditionalists" may keep the kata and other training methods the same, but not one spends two hours a day hitting the makiwara, for example. So much for keeping things "unchainged". If you leave any part of what the old ones did, you have then altered the training.
The Okinawans changed their art to fit their needs, just as if the need were here today, and these "challenge" matches were being held today, with all the innovations available today you can believe they would be doing it differently. To say that after seventy or eighty years gone by that no one has the same enginuity that the old ones had is rediculous.
As Ed brought up, Goju had undergone many changes, you can see the difference in the way kata are performed from one sect to another. Uechi was unchanged in that way, but forms were added by Kanei Uechi if my memory serves me correct. It is only today where we find ouselves not wanting to change anything. What of Mas Oyama's contribution to Karate? What about the movement he started and all the fine offshoots that have come. They may not look as pretty as some classical ryu, but the can sure open the can of whoop'em.
Manny Salazar
Submisson Sabaki