Voltage gain in the case of voltage amplifiers, usually have high impedance in (Zin) and low impedance out (Zout). This is the opposite of the transconductance amp. The voltage amp, because of it's high Zin, allows for any amount of shunt resistance to vary the load, which is one reason it's more commonly used. The Copla is unusual in that it provides a limited degree of loading by varying the current, and thus gain, through the transistor. The SL-10 has no such option, but instead uses series resistance to drop the input voltage....the gain itself is not variable.
It's a technical difference which affects the application and sonics, but yes, in effect it is still providing gain. Some consider it superior to a voltage amp, and it does have it's advantages.