I think the reason Tauchman didn't get moved is less attachment and morethat you definitely want either him or Bellinger on next year's team, and timing wise we're not going to know Bellinger's fate until November.
With PCA, even with his bat showing increasing signs of life, you have to have contingency in CF next year. You use the Tauchman = Gomes scenario but I think even more likely is PCA = Amaya. Now thankfully the org health is pretty great in CF. Even if both those things happen like we saw this year at catcher, unlike this yeat you will have Alcantara/Triantos/Franklin all at Iowa and CF capable. But still that veteran ready to step in and take primary duty is a must,