And in a "true NOS" dac, you will see it.
Nope is a filterless DAC will see it.
NOS =
Non
Over
Sampling.
The first Japanese CDP DACs were NOS.
Philips was the first one to use oversampling (4x) and did this because they could only make 14 bits DACs and wanted 16 bits resolution.
The Japanese folks could make 16 bit DACs. Of course the LSB's had issues but so did the 14 bit Philips chips.
Those NOS CD DACs had quite steep analog filters which were laser tuned on substrates.
That's why they appear to be a simple block in a schematic when in fact they were very complex.
As there was only 44.1 sample frequency this was easy.
Every designer soon found out digital OS filters were the way to go making the active post filtering much less complex and steep and thus much cheaper to mass produce.
The oversampling and because of that greater bit depth race was on.
CDP's that had 20 bits and 8x oversampling became the norm.
All CDP's were oversampling after the very first generation in 1982 (40 years ago).
Oversampling became synonymous for most folks to filtering. That doesn't mean we should not use proper naming anymore.
The folks you refer to as 'NOS fanatics' are total idiots. Still ... under the right conditions it can sound good enough for folks to like it.