At that point Auschwitz had only crematorium I with only six ovens.
The 6 mill was talked about since 1823.
Another inconsistency is that the Germans seem to have switched from using Zyklon at Auschwitz to other delousing methods right when the peak killing is supposed to have begun ramping up with the deportations of the Hungarian Jews in May 1944.
Doubtless a fabrication to facilitate Zionist political aims at the time.
Your doubts about it are themselves ideological — you affect to believe the Third Reich was nothing but nice to Jews despite its propaganda presenting them as the fount of all evil, guilty for the outbreak of WW2 etc.
Everytime I hear nonsense like: why would Jews join Hitlers Wehrmacht, I know that antisemitic notions of dual loyalty are still alive and well, among both antisemites and anti-antisemites.