Here is a clarification by way of an email on the Flynn Invitational and news on the Flynn Cup from a former member of GCA:
To clarify, the Flynn Invitational was started 10 years ago by members of Glen View club in Golf, IL. They approached Philmont about participating in the Flynn Cup but were rebuffed as were other clubs outside the Philadelphia area. Philmont was never invited to the Flynn Invitational. The participants include (West to East): Cherry Hills , Glen View, The Country Club - Pepper Pike, Lancaster, Lehigh, Rolling Green, Merion, Philadelphia Country, Cascades, CC Virginia, Kittanssett and The Country Club - Brookline. Interestingly, shortly after CC VA hosted the event, Craig Disher discovered that Flynn did not design the James River Course there. Flynn drew plans for 36 holes, but we could never match the drawings with any of the holes in a way that would allow a contiguous routing. We keep them in the Flynn Invitational because they're gentlemen and at least there are Flynn plans for their course. Perhaps Philmont will one day accept a lesser role by Flynn (if one existed at all) and eventually appreciate the significance of Willie Park, Jr.
By the way, the Flynn Cup eventually extended an invitation to Bala GC as we proved that was indeed designed by Flynn. The Flynn Invitational is trying to expand the event to include Springdale (Princeton) and of course Shinnecock Hills. It is hard to get those guys to travel off the island. Perhaps next year when the event is hosted by Merion.