One way would be for the Pokemon to already have the move it would have learned by level-up.
If you already have all the moves you wanted restored, don't bother putting it in Poke Pelago. However, since the only move it learns by level-up is Sketch, you could have three moves and Sketch and then prevent the remaining three from ever being deleted for Sketch.
Short answer: In most cases, no, there's no way to stop that.