Many top catching prospects in the mold of Moreno end up not being impact players or even average players. Look at Keibert Ruiz or Knizner.
Part of what made the trade ostensibly fair was the risk that Moreno would be useless in the short term to a contending team. But as the weeks tick on and he looks like an MLB average catcher, or better, right now, that risk evaporates. That tilts the equation on the trade heavily.
It's healthy to be open minded and change your opinions over time.