This is an interesting subject for sure. I have a ton of respect for Toole's work, but I also disagree with him on a few key issues. For me this issue is related to one of the areas in which we disagree -- the importance of treating early reflections and controlling how much they are heard.
For me it comes down to this assertion from Toole: "These reflected “repetitions” of the direct sound have a second benefit, increasing our sensitivity to the subtle resonances that give sounds their distinctive timbres."
If this assertion is the case (ie, true) then it follows that we would be less sensitive to subtle resonances that gives sound their distinctive timbres in rooms without early reflections, ie, listening outdoors or in a room with a well-designed reflection-free zone. And we know this is NOT the case.
Early reflections are known to create distortion, comb filtering, and psychoacoustic challenges. These are sonic artifacts not present in the original recording, so anything the room adds will be definition be less accurate, not more. And much of the comb filtering happens in the midrange, which as Toole notes, is where our ears are most sensitive.
For me this is a step away from accuracy, not toward.
Of course, for many audiophiles accuracy is NOT the goal. The most pleasing sound is, which may or may not be the most accurate sound. For me, the two are the same. The less the room adds to or changes the sound, the better.
In terms of treatments, again if the goal is accuracy, then for sure a balanced, well-designed treatment strategy will help a lot, with all the familiar strategies (broadband bass trapping, early reflection management, etc).
As always, I suggest experimenting in your room with your system. Evaluate what you are hearing both by ear and if possible with good measurement (like REW). I always rely on test data to put my subjective listening impressions into a more objective context.