According to
this doozy of a court case (and the hilarious footnotes) involving some guy suing Hofstra because he got WLed and ultimately rejected, Hofstra had always maintained a two-tiered waitlist, but apparently it used to be split into "preferred WL" and "regular WL" instead of "Tier I" and "Tier II". At least that's what I gather from all this.
Example footnote: "During a court conference on October 6, 2011, plaintiff stated that he chose to sue Hofstra, and not the other institutions, because it 'is the school [he] would most like to go to' and because he 'made it the furthest along in the admissions process at Hofstra.'"