A blow against censorship...but is it a good one?

The bill "includes eliminating a requirement that students be taught the “history of white supremacy, including but not limited to the institution of slavery, the eugenics movement, and the Ku Klux Klan, and the ways in which it is morally wrong.”

So, is the bill narrowly about the KKK, a reprehensible organization, or more about the "history of white supremacy"?

Having read the bill I can say it's pretty clear the intention was to suppress teaching about any of the following: white supremacy, systemic racism, the 1619 Project, etc. etc.

Don't know much about Texas K-12 that I would dare repeat in polite company. No doubt there are teachers who view their classrooms as sacrosanct protected by academic freedom.
They will ignore the much maligned Texas Board of Education and continue teaching as they have in the past.
It will be interesting to watch the response back & forth. Get the popcorn.

Actually, the teaching of history has evolved over the years and continues to change. History is always subject to new interpretations.New scholarship reveal new facts and new thinking reflective of the times (cf Georgetown & slavery.)
In a Grad School Study  I found there were at least 30+ differing schools of thought about the Civil Wear & its causes.
Late 19th & early 20th c writings tended to be pro -South during an "era of good feeling" during which the two sides joined together to try to heal the wounds. The writers at that time posited that life on the plantation was not truly bad for enslaved people and their lives were filled with happy song. In fact an early 20th c writer (Frank Owsley) sympathetic to the South wrote that happy well-cared for slaves were replaced by long lines of poor unemployed freedmen. Post war idealistic reformers who came to the South were regularly described as "Carpetbaggers" & "scalawags" ( words used by angry former confederates) in texts throughout the country. Enslaved people were described as sub human while the white plantation owners had an air of nobility.('Gone With The Wind', Margaret Mitchell) This led to the criticism (totally justified in my opinion) that although the North won the War, the South won the peace in the writings about the Civil War. Many of us ( myself included by the good nuns in grammar school) were taught in this manner. These earlier writings are long outdated and demonstrably false. (Obviously the the end of Reconstruction & removal of the Federal Troops with the concurrent abandonment of African-Americans to the horrors of white rule was a major factor in Southern post war ascendancy.)
Racism/slavery was our original sin and issues of race continue to be part of the fabric of our nation.
And, the efforts by many to deal with our problems of race and personally overcome past barriers are part of our story, too. Ultimately, it is up to each individual to evaluate, to gauge the success of the efforts - to take their stand.

I do not believe there is anyone in this country who is suggesting that we not teach about the Civil War (War Between the States to some). I think the issue is that some people believe we should be teaching that everything should be taught through the lens of racism, that the USA was built on a foundation of slavery, that people of European descent are inherently racist oppressors, that people of African descent are oppressed.

There is a spectrum of opinions & theories involved with Critical Race Theory. Also, Critical Race Theory is one thing, the role of race in our nation is another. Some include any discussion of racism as Critical Race Theory. It is not.
There are some fascinating discussions, historical & contemporary available. Historical: Was it a Civil War or a War Between the States? And, what is the significance of the use of each term? Have not heard the one about Whites inherently oppressors but I am aware of discussions of White Privilege Pro & Con. Never heard of Juneteenth in my student days but evidently it has gained in historical significance to some. The Tulsa race riot & massacre of African Americans was largely buried but relatively recent research has uncovered this ghastly story. And, the research continues with an accounting of the actual deaths and there are ongoing discussions with the descendants of the survivors.
There are many other discussions involving historical events and figures. For instance: Columbus:Hero or Villain? American and, in fact all history and its contemporary outgrowth provide fertile ground for study and controversy.
I have seen controversies come & go. Today as in the past some engage in these controversies with a different agenda on their mind. Fascinating.
Ultimately, people will decide for themselves.