Head from the Keros Haul at Auction

The head of a marble Cycladic figure is due to be auctioned at Christie's New York, Rockefeller Plaza on 11 December 2009, lot 78 [entry]. The estimate is $20,000-$30,000. The head is attributed to "the Goulandris sculptor". The head had passed through the hands of Charles Ede (2005), and is sold as "property from the collection of Mr. &  Mrs. Charles W. Newhall, III".

The head surfaced in the 1977 Karlsruhe exhibition, Art and Culture of the Cyclades, Karlsruhe, 1977, no. 172. It then resided in the Kurt Flimm collection; there was no known find-spot ("provenance unknown").

However Pat Getz-Preziosi (Sculptors of the Cyclades, Individual and Tradition in the Third Millennium B.C., Ann Arbor, 1987, 160, no. 34) subsequently placed the head in the so-called "Keros Hoard" (or to be more accurate the Keros Haul) [earlier comments of this misnomer with on-line links]. This information was repeated in P. Getz-Gentle, Personal Styles in Early Cycladic Sculpture, Madison, 2001, 163, no. 34.

The head also appears in Peggy Sotirakopoulou, The "Keros Hoard": Myth or Reality? Searching for the Lost Pieces of a Puzzle, Athens: N.P. Goulandris Foundation - Museum of Cycladic Art, 2005, 214-15, no. 210.

Why does the Christie's entry fail to mention Getz-Preziosi's / Getz-Gentle's attribution to the Keros Haul? Why was there no mention of Sotirakopoulou's study in the catalogue entry?