Will be a discussion for the CMs since we can't really quickly change out the CBM maps all the time (would have to upload the terrain each time wanted to use this grid or the normal grid). My personal first reaction is I think it over complicates things for an event especially during the event.
For example ...
Squad X where are you located?
2,10,5
Versus ...
33.30N 12E ???? (6 rows by 6 columns).
So yeah, the grid is nice for historical immersion but I think would not benefit play-ability during the event with squads trying to coordinate and report positions and contacts.
x,y,z -> 9 positions for last number (matches up to number keypad) is easier to report and locate in flight than xx.xx, y, z -> 36 positions for last number (doesn't match up to number keypad so if I say 21 takes a lot more thought to locate). Just my two cents.