I2C General Call Confusion
The meaning of 'take in' the address is for the slave to read whatever address programming lines are present on them and re-establish the programmable part of their addresses from them.

As soon as 06h is received, the devices will soft-reset and take in their programmable address from their address lines. For 04h, they don't fully reset, but simply take in their programmable address from their address lines. There is no third byte.