One of the times a unit can claim WA is when is when losing HIP status. So I don't think it needs to be recorded. Also here is some Perry Sez Q & A related to this.
B9.323
Can a gun be Emplaced in a hex with a wall or hedge hexside?
A. Of course, and Emplacement has no affect on claiming WA, and claiming WA does not supersede the Emplacement TEM.
Assuming a gun can be Emplaced in a hex with a wall or hedge hexside. Must it claim WA instead of its Emplacement modifier (+2) when an enemy unit becomes adjacent? Must it claim WA instead of its emplacement modifier (+2) if it has at least a +1 TEM (EX. woods) when an enemy unit becomes adjacent?
A. An Emplaced Gun in OG, etc., must claim WA (just like everyone else) and one in +1 TEM, etc., need not claim WA (just like everyone else). However, “when an enemy unit becomes adjacent” is not normally one of the times you can claim WA (unless you are losing HIP).
If an emplaced gun does claim WA does it receive its +2 Emplacement modifier vs units that are not adjacent?
A. It may claim +2 Emplacement TEM vs all units as usual.
Seth