My thinking is that the Protestant Reformation is still not finished. Each reformer was given light from God, but they did not fully understand it every time. As time went on, more and more light was understood, and we are now at the SDA church. I do not think that even the SDA church can stop with what we know and understand now. We must continue to strive to understand God's truth.
Some of the suggestions the article makes seem a little out of place from an Adventist view. The one that particularly got my attention was the part about the deadly wound and healing. Adventist have long understood this to be the Pope being "relived" of his position and gaining it back again from Primer Mussolini of Italy before World War two.
I would agree that the Sabbath is a key component to prophecy and very important in the last days, but I do not think that is what the deadly wound and healing is refereeing to - the Catholic Church has still not become a single unit like it was pre reformation.
I do not agree with the overall theme of Luther's errors and clinging to tradition. I believe that he was lead by God, but he did not fully understand everything God wanted him to. The same can be said of Calvin, Knocks, Huss, Wycliffe, and all the other reformers. Each one brought believers a little further away from the beast and closer to the truth that God wanted to share. That same God finally rested His spirit on EGW, and the reformation continues through her works.