This must be a (relatively) new policy. I haven't stayed there for over a year now, unfortunately, but I used to be there a couple times of year, and not only was I never charged an early check-in fee, they almost always had a room ready for me before 9:00am. I was Gold and/or Platinum over the course of my stays at the property, so perhaps it's waived for elites?
Sad to hear this development...
CLG
Can't speak to how this might unfold differently for a Platinum member, but I have been a long term Gold member and the fee definitely applies to me.
I'd be curious to know if any other SPG hotels are charging for unconfirmed early check-ins. Might make a separate stand alone post in the SPG forum.