It would be very nice to see Lilies + Misery become DPS Neutral. I'm still doubtful it'll happen though, it's unlikely to see Misery be DPS Neutral unless they make SCH's Ruin II also have to be DPS neutral since they both serve a similar purpose.

With both Glare and Broil being 1.5 sec cast time, lilies and Ruin II are going to be used mainly for being instant cast - 2 weave slots + mobility. Both still pay a DPS cost for using it.

At least, in the case for lilies, it's still healing while repaying DPS back at no cost to MP.... whereas using Energy drain for Ruin II is no longer a DPS gain anymore because Broil also grants a free weave 1.5 sec cast time, so having to use aetherflow healing with Ruin II is a lot more expensive than before.

I will have to play WHM in Endwalker to tell for sure, but I'm not too concerned with having less MP overall. Even currently in ShB, using Lucid Dreaming + Assize on cooldown is generally enough to be MP positive even with spamming Glare. You go MP negative if you have a very low piety build, so BiS would just include some piety gear to bump your required piety up a bit with Thin Air and PoM's change. If anything, having a slightly higher piety requirement on gear is better; if you ever get synced down to Lv 50 content and below, you're no longer abnormally MP hungry. Plus, the new Thin Air would then no longer feel like you have "too much MP" - which was the original reason why people went low piety builds in the first place, since Thin Air supplemented their lack of MP by giving free MP cost entirely. If anything, it'll just put a different skillcap on managing MP economy.