I'll believe it when I see it. I have my expectations very low, particularly after their little "warlocks are tanky, we want to double down on strengths, so we are nerfing your tankiness" stunt. It wouldn't suprise me at all to see effing mages get more utility whilst warlocks are told you already got utility haven't we reminded you about healthstones and portals already.
In th epast when you got good talents that are a no-brainer they usually nerf them to make the shit one slook better. So don;t be suprised to a nerf to everlasting corruption to make mana tap look less garbage
And it wouldn;t supris eme at all to see them decide that Soul Flame is "too good" but to leave the whole on-death reliance clusterfuck untouched. Remember this is the same Blizzard who gutted the Soul Reap mechanic right at the last minute so they didn;t have time to fix the fact that the whole damn artifact is designed around it.
That's why affliction is so crap in pure single-target fights: not only is it's base damage low, to stop multi-dotting getting out of hand, but the artifact does hardly anything to help. Soul Flame and Wrath do literally nothing whatever, and you are starved of souls to power up reap. And yet when it comes to AOE, where affliction is strong, you are drowning in buffs and souls, on mythic+ trash I've got the on-kill buffs up almost all the time and there's an endless supply of tormented souls.
Same with destruction, it's all built around Wreak Havoc, it is tuned around that, so any time you can't cleave all the time you're boned; look at the logs for pure single target, and there's destruction right with affliction keeping the tanks company.
Last but not least most people sensibly dumped the class and thus warlock is now very low population, so they aren't going to put in anywhere near the time and resource they are going to put into fotm classes like mages. Basically warlocks have fallen into disuse and would require a huge effort to make them attractive again.
Basically it's all snowballed, clas sis bad, peopel don;t play it, why bother to sink time and resources into fixing up something hardly anyone plays, so it stays a class most people won't touch with a bargepole. All helped along by the terrible reputation we gained from the first month of live and will never shake off, the message is out, play a warlock and groups don;t want you.