Repairing walls and gates will no longer award event participation. This alleviates the behavior we've seen in farming Objective Scaling Rewards and "wasting" supply while defending. However, an additional side effect of this is that repairing alone will not progress achievements that require event participation, such as Keep Keeper, Nice View, or Stay Out.
Nice change for smc supply wasters, but kinda sucks for those doomed tower defences.