Now there is a “summarization” category, but the dialogue domain is different. Moreover, there are a lot of  models already (most of trained on the SamSum 2 datasets).
Even though we have a Text2Text Generation 1 tag, it is very probable that dialogue summarization will become bigger and stronger.
I believe it is reasonable to create a new category, but I’m not sure how. I think it should be done my the admins or someone.