Roster management is not always straightforward. The FO must weigh what's best for the team right now, what's best for the team in the long run, and what's best for the player himself.
Fortunately in this case, sending Eddie to AAA, to try and straighten out whatever's wrong with his approach at the plate, checks all of the boxes. As a bat-first player, he needs to hit, period. He's doing no one including himself any good with what he's done so far this season.