Whilst 'smart' behaviour might enable the phone to switch on some such functionality when the SoC/CPU is put under heavy load (by something such as a game), the effect of such automated switching is unlikely to have anything like the effect of a hardcoded force-to-high-power-mode as shown here.
It just guarantees that it will happen in that case. Unless you have some reason to believe that this mode is unattainable under any real world circumstance, I think the original point still has some credence.
I would guess that the high-performance mode drains the battery so quickly, or creates so much heat, that it's impractical for general use.
Based on the fact that they are Samsung. That they aren't transparent about what they are doing. That there is no evidence that these optimization kick in in other contexts.
They are doing something to fuck around with benchmark numbers, the onus is on them to explain it and be upfront about it.