If that were the case, pet Basic Attacks would proc it, as they are “damaging abilities” that your pet is using on a target in the area. Tooltips have never been a 1:1 with reality. Adrenaline Rush for Outlaw still makes no mention at all in the tooltip that it reduces the rogue’s GCD from 1.0s to 0.7s for the duration.
That said, the ability does still suggest what they appear to be going for. “Each damaging ability you use […]”. In this case, you’re not using Serpent Sting, it’s merely occurring passively in the background. That’s why I’m saying 1:1 ability casts to procs is rather clearly their intent, and they’ve made active effort towards that.
And a specific counter-example in this case is that Blizzard did make a change shortly after Wild Spirits was revamped to make Double Tap not trigger a second proc. If the second Aimed Shot from Double Tap clearly is not intended to count, why on earth would a second shot due to a legendary?
Still, it doesn’t freakin’ matter if it was a bugfix or not. They fixed a bug with Wild Spirits double-dipping on MM’s mastery, and they compensated it by buffing Wild Spirits damage by 25% specifically for MM, because MM was tuned around it. When they nerfed Deep Wounds to rein-in Arms AoE in BfA, they compensated with a substantial increase to their spec aura and thus their direct damage.
So whether they considered this to be fixing a bug or a targeted nerf to an overperforming legendary/covenant combination, doesn’t matter in the slightest. They clearly acknowledge that bugfixes and targeted nerfs both require compensation if the class is tuned around that combination and is in a good place on damage. That leaves only a few options:
- Their tools/damage sources show hunters doing much better than the sims and logs do, and they trust their tools over actual game results.
- They think MM was overperforming even in single target, and intended to knock it down by ~3% on single target DPS.
- They are completely negligent and terrible at their jobs and simply haven’t noticed that all 3 hunter specs are now literally garbage-tier.
- Ion actually bona-fide hates hunters and enjoys punishing us and making us suffer because he got one-shot by a hunter one time back in WotLK or something.
Honestly, I’m really not sure anymore which of those is more likely. I used to think that Blizzard being incompetent or the devs hating us were just player cynicism coming to life, but honestly, these days, I’m not sure I believe that anymore. Warlocks are literally the second best spec in the game, and their targeted nerf was reverted within 24 freakin’ hours on the PTR.