It's not a money thing.
They ended handing out hardcopys three years ago; just releasing the electronic book at the convention, with hardcopys to be ordered by the publishers later. This is how it was done with the revised Bible Stories book last year.
It's more about releasing things at the same time to everybody.
With Regional Conventions stretching from May to January plus the publications being available only from the first convention when you click properly or improperly.., the idea of new releases at the RC is outdated. So they practiced this thing already with the 2013 revision of the NWT, the revised Organized-book and the light version of the God's Love-book: release it at the AGM, make an announcement worldwide at the next LMM and everybody is in the know, as the publications are already online.
In 2001 they announced the new TMS book to be released in 2002 and to be used in 2003... now they announce the revised brochure, immediately available, hardcopies to be ordered this month in order to be used in January. That move makes sense.
Only thing I don't get is why the Ezekiel-book is available in English only as for years they made a tumtum that they release everything simultaneously in dizillions of languages..