Hiding the unit won't immediately desync. However, it can desync upon certain interactions.
Here is one scenario: You make a pally owned by player 1 (red). You hide it for only player 1 (red). Once player 2 (blue) selects the mountain king, player 2 (blue) will be disconnected from the game.
So I just advise you to test this a few times to make sure it works for you. Otherwise you should resort to another method, such as invisibility.