My biggest concern is, in sports as 'crowded' as basketball, hockey, football, how to ensure the auto-detect pics up on the person I want. I'm sure, in the end, it's very similar to how I try to put the focus point on a player with my 5D3. It's just going to be different enough to require a little learning / retraining.
On cameras with the newer AF system (R3, R7, R6II) you can customize the size/shape of 3 AF areas and set a button (eg MFn) to scroll through those AF areas. I think this will work really well for hockey which I have some experience shooting.

