The speech Havok is listening to is from Uncanny X-Men (3rd series) #4.
While the past Cyclops may be aware that he has a brother, at the point the original X-Men were pulled to the present from, Havok had not yet debuted and Scott had apparently kept the information from his teammates.
Additionally, at the time the original X-Men were pulled to the present from, the Scarlet Witch had not yet joined the Avengers.
The Scarlet Witch said “No more mutants” during the House of M.
As revealed in the Avengers: Children’s Crusade mini series, Wanda was under the influence of dark magic conjured by Dr Doom when she went insane.
Mystique met the past Cyclops in All-New X-Men #7.