Welcome! Had not heard of the Royal Empress, before. From what I read in a few minutes of study- it is quite invasive and next to impossible to kill. My guess is that your trees will recover nicely, in time. I would take a wait and see attitude... Good luck!
I hadn't heard of them either and googled it. It looks a lot like what we call China Bells, although I am not certain it is the same tree. Beautiful anyway! I can see why you like it.
and I hope someone here can get an answer for you.
Beautiful tree. Just don't plant them where you park your car, near power lines or next to your house. My sister just had to pay $1500 to get one removed. It had a rotten core due to improper pruning. It dropped a limb on her new car
It was too close to the road, house and power lines to simply cut down and she had to call in a specialized tree removing company to remove it. $1500 was the cheapest bid for a licensed and insured removal.
I think they are very beautiful trees, but just be careful where you plant them.