This was only bc the frequency band for vocals are more pronounced on the 9200 compared to 7200, which creates a different perception how vocals are sorted on the headstage.
The biggest impact on vocals comes from the recording itself, imo.
The vocals on the 7200 are more "laid back" than on the 9200 (like the highs too), which is a benefit for long term music enjoyment, I'd say.
But again, it depends on the volume level you're listening whether it suits your preferences or not.
I am a low volume listener, so the 9200 is a great headphone for my use case, but I still miss the 7200 for its long term capabilities.
Thou sometimes, the bass of the D7200 on certain tracks was too much for me. ^^