Looking for a definition here. Also what is a Pro event? There doesn't seem to be anything that defines a pro player or a pro event in pool since anyone can pay the entry fee and play in any tournament except for maybe a couple of exceptions.
Until there is a line drawn in the sand that specifies all those standing on the left side of the line are to be considered PRO by skill level and have in fact separated themselves from the rest of the crowd standing on the right side of that line defined as ALL others....there is no such thing as PRO players.....there are only players that play at a high level of skill and those that THINK they do.
As far as Pro events, until the first requirements of a players eligibility to enter the tournament is that the player is standing on the left side of that line drawn in the sand....tournaments will always be considered to be open events to anyone willing to pay the entry fee to join.