Well...not sure, because no one has yet denied the networking theory that states "impedance matching" issue.
They will driver headphones, sure, but at the cost of reduced sound.
Once more, Samsung and others probably use optimized solution for theirs products.
I think you misunderstood 'impedance matching' or the one writing the article misunderstands.
A: The 32, 80 and 250ohm DT770 not only differ in impedance but are not the same in frequency response, the 32ohm has different pads (pleather instead of velour).
B: In many studio gear the output impedance is (sometimes much) higher than just a few ohm. In this case it is not a matter of 'impedance matching' but a voltage division issue due to the varying impedance. The effect is 'worse' for lower impedance headphones resulting in boomy elevated bass. The higher the headphone impedance the less the effect. So the 250ohm can be connected to low and high output impedance amplifiers without changing tonality (much). The 32ohm version will sound different from different output impedance amplifiers. The 80ohm is 'in between' both in impedance dependency and sensitivity.
Most headphone outs from phones/tablets just use a low voltage op-amp on the output. Not a class-D output intended for speakers.
Furthermore they usually run on just 3V or sometimes +/-3V or so (using a charge pump for the negative 3V) limiting the output voltage of said devices. Because of this they also can provide a bit more current so are very suited to drive low impedance headphones but are less suited to drive high impedance (less voltage sensitive) headphones to higher SPL resulting in poor sound at higher SPL.
As phones/tablets have very little board space and low power rail voltages they use IC's like: MAX4410DS, MAX97220, TPA6138, TPA6139, TLV320, TS 482, PT2309, SA58635
Not the usual op-amps nor higher power headphone driver ICs.
And yes, you can parallel an 18ohm to a headphone when using a class-D amp (for some silly reason) as a headphone amp.
This won't affect sound quality.
The sound quality (distortion) usually is lowest driving higher impedance headphones. That said, higher impedance headphones, in general, require a bit more voltage (have a lower sensitivity) to play somewhat loud which portable devices cannot provide.
