I suppose it makes sense that the more you understand something, the more you value it. Most or all teams would have really good defensive metrics, especially for outfielders, with the Statcast data. Maybe before teams were pretty sure Player X was provided real defensive value, whereas now they are certain and therefore are willing to pay a higher price.
But yes, moving him back to CF makes no sense as it will really crush his value. He won't be a good defensive CF.