dpreview has updated their studio shot comparison tool with Sony a6500 flagship mirrorless camera. Here is high ISO comparison on Sony a6500, Sony a6300, Nikon D500, and Fujifilm X-Pro2. All these images are taken at ISO 51200 in RAW model.
From the images above, we can see the Fujifilm X-Pro2 and Nikon D500 has better performance than Sony a6500 and a6300 in low light model.