As mentioned, the risk of DL punishing you is nonexistent. Unless you're on DL's radar (and very, very, very few people are), it will go completely unnoticed.
The only risk you need to be concerned with is operational irregularities. I've been burned several times; for example, last year I booked LAX-DTW-IND but on the day of departure, the LAX-DTW leg was downgauged to a 763 to 757 and I was rebooked on a direct LAX-IND that left around the same time (and no, no compensation is due).
Be prepared and have a backup plan if things go wrong.