How strict is Delta with carry on luggage?

I’m going to be traveling internationally tomorrow and I will be talking my violin with me. I’ve made this trip multiple times before with Delta and different airlines. I usually have a carry on suitcase along with my violin. I know that my violin is supposed to be considered my carry on item, so I shouldn’t have been able to bring my suitcase in the past. However nobody has stopped me before. Recently I heard that Delta has became more strict about carry on luggage and I’m wondering if that’s true. Should I not take my carry on luggage with me tomorrow and only take my violin and personal item?