Brakes Auto Bleed procedure

[Vas62]

The vehicle is 1995 Bonneville SSEi.
After changing brake pads I noticed when start braking the pedal is too soft and it's better braking second time after pupmp it once .The guys at shop didn't bleed the brakes or even open master cylinder when changing pads. There are no visible leaks.
CHILTON repair manual states " ..for 1994-1999 vehicles with ABS ,after bleeding the brake system you must perform an "Auto Bleed" sequence ,using a Tech1 or equivalent scan tool. If you don't have access to a suitable scan tool,your vehicle will probably have to be towed to a shop with the proper diagnostic equipment to have the procedure performed".
Any body knows what's is it all about this "Autobleed" procedure and if this is a must?
Thank you in advance.