Stargateheaven confirmed that he saw no option for Advance Swing(s) in his broadcast yesterday, nor any hint of it as an add-on unlockable after 10 hours of play. Another viewer in his stream (ncaa380) confirmed that he'd gotten official confirmation on NO Advanced Swings months ago.
Their information was convincing enough to convince me to cancel my pre-order. I've seen nothing since then to dispel that.
It's disappointing, if true, that alternate swing styles aren't somewhere in the game, but certainly not enough for me to cancel my pre-order. The game is just too much fun. It's going to be very well supported with new courses etc going forward. Hopefully the alternate swing mechanics series veterans are asking for (I'm a circle shot guy) will arrive in an update.