My T has been through something similar. I think it has both positives and negatives.
She can relate better and knows how I feel and what to say. I feel more free to share my experiences and feelings.
On the other hand, sometimes our experiences are different and she tends to project her stuff on me. She assumes some things are the same but they aren't. My experience was different. Her pushing certain views or perspectives that were true for her but not me vám be extremely frustrating.
Still, I prefer a T with a similar trauma.