25.05.2017, every update since that is not included.
That information is simply wrong.
According to Cruzz file:
brummbar_squad_mp
AOE
AOE Radius 6
Distance near 0.625
Distance mid 1.25
Distance far 6
Which was actually patched in Update: 17th of May 2018
Brummbar
The Brummbar is having its AOE adjusted to reduce its ability to wipe out full health units on the first shot, but still able to deal significant damage on misses.
• AOE distance changed from 1.25/2.5/3.75 to 0.625/1.25/6; applies to both auto-attack and bunker-buster
• AOE damage changed from 1/0.3/0.05 to 1/0.35/0.2; applies to both auto-attack and bunker-buster