I little history lesson might be relevant here. Czerny used the fact that he was a pupil of Beethoven, and recording Beethoven's interpretation of Bach for posterity, as a major selling point. Beethoven certainly saw a few copies of Bach's music that had survived in the Imperial Court Library, but at that time, Bach's entire musical output was unknown and unplayed. Most of it had never been published, and finding a few handwritten manuscripts that had been copied (and probably altered) an unknown number of times by unknown people was not exactly a definitive record of what Bach had intended. Czerny and Beethoven had nothing to guide them beyond pure guesswork. Bach's keyboard instruments (the harpsichord and clavichord) were as obsolete and unknown as his compositions for them.
Czerny's editions of Bach are interesting as an example of an indisputably great musician (Beethoven) trying to make sense of something totally foreign and close to incomprehensible, but compared with modern editions based on (infinitely) better historical research, they tell us a lot more about Beethoven and Czerny than about Bach.
This http://www.bach-cantatas.com/Ref/BWV772-801-Ref.htm gives some idea of the amount of contemporary research - and note that new facts are still coming to light, and opinions on the Inventions and Sinfonias have changed even within the last 10 years. Beethoven and Czerny knew none of this.