I haven’t read the book, as I was never a big fan even of TKAM, which I only read because I had to for high school. However, I have followed the controversy. I’ve also heard that Harper Lee herself now suffers from dementia, and therefore, we’ll likely never know if she meant for the Atticus of GSAW to be the exact same character as the Atticus of TKAM.
But I do think it’s important to be aware that GSAW was written before TKAM. Hence, it is NOT actually a “sequel” the way most of us would define it.
So, just because Lee portrayed the Atticus of GSAW as a racist who believes in segregation while still believing “equal justice”, does not mean that when she wrote TKAM, she still meant for him to have these views. She could have, she could have meant for Scout’s POV to be completely unreliable, and I do recall when I read TKAM that she DID seem to idolize her father in a way that seemed a little “off” for me.
And certainly, one can argue that believing “innocent black people should not be railroaded into jail or worse” is a very basic civil rights point, that a man could hold, while still thinking it best if the races didn’t mingle.
Or, Lee could have re-formulated the Atticus character to actually be, or at least close to being, the paragon of virtue that Scout saw him as. That’s also possible.
Though I also recall a speaker who spoke at some event in HS, I believe sponsored by the African-American club, and stated as if it was obvious fact, that Harper Lee herself was a racist, and that TKAM itself espoused racist views. (In a general rant about how most white people were racist.) She never even bothered to explain why, it was so obvious to her. But perhaps she thought that Tom Robinson’s end was a cop-out that let Atticus off the hook for his failure to actually secure his freedom, and played to racist stereotypes of black people as lawless, as Tom Robinson is eventually killed trying to break out of jail.
As to the whole controversy as to how the book came to be; I’m no conspiracy theorist, but it is interesting how the book is being released at a time when race relations are so strained again, and it seems some non-white people, see white people as all essentially, unredeemably, racist at the core, that even those who don’t seem that way are just hiding like Atticus. And that Atticus’s attitude toward “negroes” might be compared to some conservative beliefs toward homosexuals – “So you claim you don’t support gay bashing and bullying, and I guess you wouldn’t want a gay person being sent to prison for a crime he didn’t commit. But if you don’t support marriage equality, then you’re a homophobe just the same.”