KCWO the week before, Masters Cup the week after. I wonder how many pros made the choice to head back west after KC in lieu of this event. I'd be willing to bet the number is fairly high.
With, I believe, an A-tier on the weekend between, and on the way west.
The timing of the American Open is one of the very many head-scratchers, though we don't know what constraints they were under. It seems doubtful to me that ESPN3 limited their options, though Cobblestone might have. Or perhaps it was just their non-PDGA, anti-PDGA stance that resulted in the awkward scheduling.
Attending all 3 (KCWO, ADGT, and MC) is quite a bit of travel, but perhaps some players---particularly eastern players, especially those from nearby---will skip one or the other of the PDGA events, replacing it with the ADGT.