Given a provisional title of "Book 4" when it was solicited last spring, it would have included #'s 64-74, plus ANNUAL #2 and the Doom Patrol story from VERTIGO JAM (1993). It would have had ISBN#  14012-7451-X [or 1], but also would have had nearly 400 pages for $39.95. The page count of the Annual and the short story averages out to about two normal issues, so the remaining uncompiled issues (#75-87) would fill a hypothetical second volume (provisionally called "Book 5"?) roughly the same size and price. According to the Newsarama account, the title will not be resolicited. It's just my own speculation that the price might be intimidating. Whatever the actual reason, DC likely wasn't committed to the project since the Amazon page for the book still has the cover of Pollack's first issue (#64) complete with March 1993 cover date and $1.75 price clearly visible in the upper left hand corner standing in the place of whatever cover art the book would have had. It wouldn't have been a bad idea for the trade paperback to use the same Brian Bolland art used for the cover of #64, but DC never bothered to use a reproduction without the comic's now 25-year old trade dress.
I'm hoping that the reason it "won't be resolicited" is that the followed the reasoning I suggested eight years ago in this blog, recommending a three-volume configuration, which would likely mean each costing $29.95. Three books for $90 versus two books for $80 might, counterintuitively, get higher orders. People always pay more in installments. Call it a mortgage. See the break down here:
DP05-AA Pollack Period synopsis