The B division already have it, but not for all lines. The has it like the A division, but the other lines that have train arrival signs use them in a different way.
The IND Eighth avenue, IND Queens Blvd, BMT Broadway, BMT Astoria, and BMT 4th Avenue lines have at least one station with a similar function to the A division arrival signs. Instead of saying when the next train arrives, they tell you how many stations a local and/or express train is from your current station. As far as I know, the only station to say a specific line is 175th Street on the downtown train only.
Edit: Apparently, another 267 B division stations are planned to be equipped with arrival signs as part of the 2015-2019 capital plan, but with the problems with the plans already, this is subject to change.