The problem before the nerf was that it was one of the RNG units that could wipe squads without warning, player action or resource cost (a precision strike at least costs resources and requires player actions). Plus it was basically impossible to take out.
Before the nerf I was advising for the unit to be toned down.
Here are the patch changes:
Cost from 360 MP to 400 MP
Range from 120 to 100
Scatter ratio from 0.1 to 0.15
Distance scatter max from 14 to 15
In my opinion, the nerf completely missed its target (how fitting...) beyond the change to scatter scaling (loses accuracy quicker with increased distance, had far too low scaling before the nerf). It didn't really change anything about the explosion radius or its damage, mainly just changed values that were no problem to begin with.
It is just as much of a RNG weapon as it used to be. It will still one-shot squads without warning, it just won't do it as often.
Most of the changes to it were really just to make it undesirable without fixing the problems the mortar had.
I think buffing it would be the right step to go. Preferably with changes to its RNG nature.