I wouldn't say it's the future at all but this is a good design and architecture if you are building custom, one of a kind amplifiers.
This architecture separates the the L/R channels and power supply from the amplifier section and allows easy to access to the components.
Think how much more complicated this wiring would be if all the inputs, outputs and power supply were all in the back, and the signal having to travel through the power supply to get to the input tubes and then back past the P/S again to reach the speaker taps:
Warning: Spoiler! (Click to show)
It's form over function!
And I like the bakelite knob...which is an easy swap anyway...cheers!