Deflection after the buzzer
 

Player A makes a try for goal with 1 second on the clock and clearly gets the ball away before the buzzer. The Buzzer sounds while the ball is in flight
After the buzzer begins to sound, Player B deflects the ball but it still enters the basket.

Do the points count for Team A?

Yes, neither the buzzer nor the touch by the defender end the try. Also, if the touch happened to be goaltending or basket interference, it would be enforced even if after the buzzer.

Team B's simple deflection does not end the try. Now if Team A had deflected the ball, then the try would of ended and so would the period.

Just Kidding ...
 

See Rule 4 for the differences in the definitions of simple deflection, and deflection.