As more pixel density often means more noise at higher ISO’s, it was one of the first things I looked at when I received the X-Pro2. To put you guys (and girls!) out of your misery, it does definitively not disappoint!
On my X-T1 I have absolute no concerns shooting at ISO 3200 and will bump it up to ISO 6400 if really needed; the same is probably through for X-Pro1 users. With the X-Pro2 this has now changed to, “no concerns to shoot up to ISO 8000 and I’ll bump it up to ISO 12800 if needed”.