Rwwear, in the real world, people want to use OTLs with low impedance speakers. If you use an autoformer to do this, you often meet with success. The fact of the matter is that the autoformer has bandwidth that is wider than most amps, tube or solid state, which is only possible because its turns ratio is so low.
IOW, using the ZERO would not be practical if you did not already have a low output impedance and no DC at the output. So that could be an OTL, but it could also be a transistor amp. Its already been shown that a transistor amp will sound better driving 4 ohms or less if it does so through a set of ZEROs rather than direct.
So the argument holds regardless of the amplifier technology, which inherently includes OTLs.
IOW, using the ZERO would not be practical if you did not already have a low output impedance and no DC at the output. So that could be an OTL, but it could also be a transistor amp. Its already been shown that a transistor amp will sound better driving 4 ohms or less if it does so through a set of ZEROs rather than direct.
So the argument holds regardless of the amplifier technology, which inherently includes OTLs.