Just recently conducted a fun test between the two camera's at an indoor fast spinning amusement park ride.
The 80D w/ 24-70Lmk2 took the win drastically producing extremely high keeper rate over the X-T2 w/ 16mm or 55-200 lens. Perhaps not an apples to apples test but the X-T2 struggled tracking my daughter. The 80D effortlessly tracked and acquired focus with ease. I produced alot of blurry miss focused images with my X-t2.
Everyone's needs are different. In most cases I'd assume the X-T2 will produce fast enough AF for most applications. The fun AF test I conducted truly showed me the limitations of my X-T2 vs a mirrored 80D which technically isn't a top tier sports camera.
I'm hopeful the new firmware will improve the AF speed. I was actually quite shocked how poorly the X-T2 performed. I must try to find the best AF-C custom settings to see if I can get better keeper rates with the X-t2. Quickly trying all of them I still did not even get close to the keeper rates of my 80D.