Authenticity is one of the possible criteria to judge an edition or a recording, and certainly very valuable, but not the only one. Just one example stares at

Authenticity is one of the possible criteria to judge an edition or a recording, and certainly very valuable, but not the only one. Just one example stares at you from the Wohltemperiertes Klavier itself: physical evolution of the capabilities of musical instruments. This work itself was in part a demonstration of a new tuning theory. It would have been impossible to play in all these keys just a few years earlier. So the question can also be framed as a kind of exegesis: Bach might have wanted the Wohltemperiertes Klavier to sound in an entirely different way given a different context. And while propagation error is certainly a risk with lesser known composers, in the case of Bach, don't be too afraid of it. At all.