Hey there are teachers at universities that teach that the 9/11 attacks where a plot by the US government and they get defended on the grounds of Academic freedom.
Try reading the article you linked again. The Geosciences professor is not teaching the 9/11 conspiracy theory, she is exercising her freedom to publicly speech her opinion.
So do you want the government to tell teachers what they can and can not teach?
Short answer, yes. Long answer, the government does not need to micro-manage public education down to every minute detail but they do need to set some type of standard.
K-12 is only a primary education and the students, and often even the educators, almost certainly lack the time, knowledge, or materials to effectively question or critique generally accepted scientific theories. Once the exit K-12 should should have the necessary foundation to enter a university where they can then effectively engage in serious research and critique.
Evolution is generally accepted as is gravity. Newton's laws of gravity are known to be inaccurate but the theory is generally accepted, accurate enough to be useful and easily taught in the K-12 program. You don't throw out Newton's lessons and insert Einstein's relativity theories as the math required exceeds the ability of most K-12 students and educators. And relativity is not perfect either, but you would not expect K-12 students to spend their class time trying to develop an accurate theory when they don't even know what a theory is, how science works, or have virtually any of the tools necessary to perform such a task.
Standards are necessary, teaching the controversy serves no purpose in K-12, and lets be honest, everyone knows the purpose and intent is to replace science with religion which would be damaging. God done it is not an acceptable answer from a student who completes K-12.