May be the same type of issue which kept the title from being released in the VHS era. Such a shame as this film is absolutely delightful, and I was planning on buying 2 copies.
Somebody uploaded "Centennial Summer" on the 'Tube a while ago - from one of its airings on AMC. This title was probably amongst those which had their original colour elements junked by Fox in the 1970's, but I'm expecting great things from TT.
Very disappointing that only a handful of us...