Is "detailed" audiophile code for too much treble?

No, detail(ed) is not synonymous with bright.  And a system can sound bright without being detailed.

In my case, it depends on wether it's digital or analog. Overall, highly detailed in digital leads to some fatiguing in my experience. I easily remedy it by using sine wave from my master clock to all digital components. Square wave is just too sharp to my ears and conducive to distortion. In my analog system, I do not ever really suffer from too much detail.

Bright gives me a headache or fatigue. Detailed does not necessarily have that same physical effect. A lot of times it does but when it does not, I keep that gear.

It’s hard to be detailed if not bright ie dull. For proof just Turn down the lights and watch the detail fade away.

Higher frequencies enable detail.   That’s just how it works.  But the devil is always in the detail. 

I never interpreted the meaning of "bright" when used in the audio vernacular to be the same definition as when used it the discussion of the intensity of a light.  But I may have been wrong about that; I often am.