Is this linear amplifier topology regarded as Class B amplifier?
Circuit 2 is not an amplifier topology. It is called a half-bridge, not an amp. It will only operate properly digitally. It is a building block in inverters, motor drives, and class D-amps.
However, there is more to it than what you have drawn and it is not driven the way you have drawn due to technical issues. And often an NMOS is also used on the top side.