Pro golfers are generally a conservative group. Surely as far as professional athletes go. Additionally, the Tour Championship is a big money event, and usually determines the Fed Ex Cup winner (which I believe is $10M), and is a limited field event in that only the top 30 players participate. So I don't think it will be an issue for the players.
That's why the PGA is not joining in with MLB. Most professional sports have players who are mostly Leftists and that scares the crap out of those sports' owners. The owners are cowards and have allowed the players to be in charge.