Status mitigation in general has been crippled in usefulness, yes. It's not just the fact that everything does AoE damage + multiple statuses, though, although that is a large part of the problem. It's also due to those damn aura effects becoming commonplace. The fact that you can't remove aura status for more than a couple seconds at a time is bad enough, but the fact that a status that will just bounce back can chew up your "only removes one effect at a time" spells is even worse. On top of that we are bombarded with more unremovable statuses than ever before--Weakness, Terror, Muddle, Encumbrance, Amnesia, and even run-of-the-mill statuses that have been made arbitrarily incurable like the Paralyze from Wings of Agony or the incurable Plague from one of Bhishani's TP moves.
Now obviously all this is a general problem for all WHMs, not just a few dozen Mythic owners. But with status removal being Yagrush's main augmenting focus, it's really taking it on the chin. Not only that, but a Yagrush WHM is expected to be in the middle of the auras and TP moves dishing out this crap, which a normal WHM isn't. It's completely untenable. Any changes to Yagrush need to take into account that the Yagrush WHM is going to be in the death zone. For a start, I'd suggest an enhancement to Yagrush that lets the wielder have both Afflatus: Solace and Afflatus: Misery (for the stronger Esuna) up at once, and have the Stoneskin effect from Solace apply to Curas. Also, since Esuna is already AoE and won't benefit from Yagrush's main trait, it should receive a further enhancement to number and/or type of statuses removed.
They could always make the final augment to Divine Benison make status removal full on Quick Magic/Chainspell speed, I guess. Seems excessive? Even Chainspell Erasega won't seem too strong when the mantis you are fighting decides to start spamming Macerating Bile.
Saying that SE has anything "in mind" for Mythic weapons at this point at all seems a mite too generous. I really don't think that they care.
With status removal being near-vestigial these days, you're basically talking about giving Yagrush a completely different role here. Still I'd agree that making Haste AoE is a necessary reduction of pointless busywork for any WHM that is going to try to make any use of the weapon's Aftermath property. That was probably the rationale for the original 100% AoE -na enhancement on Yagrush, actually.