There are at least half a dozen nice statues that were put into the game that mostly collect virtual dust in the star menu. In comparison, other games provide players bonuses through items that can be placed on islands. This may be a way to make the statues of more use to players, encouraging use. These could be either permanent buffs with placement or zone buffs along the same lines that have just been recently added to the game.
Some ideas for the functions of statues:
Angel Gate Monument: Transports generals to other islands more rapidly
Horseman Statue: Generals move more quickly on the map
Soldier Statue: Bonus to combat or bonus to troop production
Merchant Statue: More trade slots in the trade office or increased treasure rewards on adventures
This could also be used for the multiple, currently functionless, rewards received from the events, such as trophies or statues. They would be much more sought after even will relatively small bonuses, such as 5% decrease in troop production time or 5% decrease for population growth buildings.