I think this is just more proof that the role of darklight weapons has changed since 8th edition. They used to be anti-tank. Now they do best against big monstrous creatures. I play against Deamons a lot, and the things that that player fears most are darklight weapons and my Talos. (and soon maybe my Grotesques, but he doesn't know that yet...)
Anything with Haywire is great against tanks, that is nothing new. The only thing that matters is what units with haywire fit best in your army. Skyweavers are great, but you need to fit in a Harlequin detachment, meaning you need to ditch at least one Drukhari subfaction. Talos with haywire are great, but not allowed in Ynnari. Scourges may not be the best, but they are flexible, and can deepstrike for free. Something that won me my last game, since my opponent completely forgot about them (I did announce they would come in that way when we started) and gave me an opening to drop in, take an objective while bringing the hurt big-time.
And the Reapers Storm Vortex may not be called a haywire weapon now, but I definitely count it as one. It's the best anti-tank weapon we have, except it suffers from a huge bulls-eye painted all over it, and being a paper boat. It requires the right tactics to use, or it will be one of the first to die.