If the enchanted creature gains an ability after Utter Insignificance becomes attached to it, it will keep that ability.

Utter Insignificance overwrites all previous effects that set the creature's base power and toughness to specific values. Any power- or toughness-setting effects that start to apply afterward will overwrite this effect.

Effects that modify the creature's power and/or toughness, such as the effect of Wing It, will apply to the creature no matter when they started to take effect. The same is true for counters that change its power and/or toughness and effects that switch its power and toughness.

Because damage remains marked on a creature until the damage is removed as the turn ends, nonlethal damage dealt to a creature may become lethal if Utter Insignificance becomes attached to it during that turn.