Yes it does participate. I had the same concern when booking for a stay this past June when I saw that message. I called the hotel and the guy I spoke to was surprised that the website was giving out that message and he assured me that they fully participated. I did in fact receive points for the stay.

Having said that, you'll see by doing a search here for other threads on the property, that they give plats a minimal room upgrade, if any. It is a very nice property though.