This would basically be DC renewing the copyright on the title Batman Family. Every now and then, DC puts out a new comic with one of their old titles, just to keep the copyright alive on that title. This collection of the Bat-verse Elseworlds Annuals would be the perfect opportunity to put Batman Family on a graphic novel. (The 2002 Batman: Family has yet to be collected into a TPB.).
For the cover, I'd use Robin Annual #3, because it shows versions of Batman, Robin & Catwoman - showing the most members of the Bat Fam of any of the covers.
Would you buy it? Let me know in the comments, and thanks for reading.