No this was after the patch around a year ago, there is no mention of any nerf afterwards in the patch just ctrl+f tank hunter or precision anti
I blame it on the spaghetti code as always
I don't think the PTAB run was touched at all, it deals more or less 1/2HP damage of heavies depending on RNG bomb scatter. It's the same as in the vid you posted. PTAB is better when used against large vehicles as they get hit with more bombs. It kills inf very unreliably mostly causing moderate HP damage, but that's ok, as it's mostly an AT run.
The point that people are missing in the comments above is that Butterfly Bombs don't hit all at once so if you are lucky you run over the area that is not exploding right now. In working principle it's similar to OST Light Arty Barrage. First shells/bombs come early, but they don't come all at once. It saturates the area over time. If you are lucky, you can run through Butterfly Bombs with some damage taken, but you won't get wiped, meanwhile any infantry caught within Frag Bombing Run are dead, no exceptions. Also with the Frag Bombing Run you have to see the plane to identify the direction in which you should move your infantry/teamweapons. In the test that Shadowlink performed, the AT guns were ordered to move when the smoke appeared, even before the direction of bombing was known. Was the plane coming from SL base, these AT guns would have been wiped.
I appreciate the testing done, I don't like how Butterfly Bombs are implemented but per abilities used, I have suffered and caused significantly more and more meaningful wipes with Frag Bombing Run than with Butterfly Bombs.