Agree with the Straw Man article of the day comment.
Protestants don't teach scripture alone. But scripture is authoritative, because it was written by prophets and apostles. Scripture itself tells you that the Holy Spirit was sent to convict us and to remind of scriptures. Scripture itself also commands believers not to forsake fellowshiping together. And tells us no scripture is of private interpretation. Thus church helps us with interpretation, and helps us with understanding the right context.
So this understanding of scripture and church does not preclude doctrinal development?