I'd like to talk a bit about Z status moves that restore health. These are important for various reasons. One of which is the intense need of many mons in NU to have recovery. We've seen in past theorymonning how recovery can be useful. This gen Mantine gained Roost and it is expected to fly away to higher tiers. Recovery is a big deal in NU. While GF might have not given recovery to all new mons, they did give at least some options in Z status moves that restore health. These include: Heal Bell, Refresh, Psych Up, Stockpile, Spite, Curse (if used by a Ghost type), Haze, Mist, and also Aromatherapy (but all mons with Aromatherapy already have recovery moves), Conversion2 (which only applies to Porygon), Transform (which only applies to Ditto and Mew and they will never use it) and Belly Drum (which has already been covered to some extent). So I'd like to talk a bit about remaining moves.
Z-Heal Bell is great for bulky mons that don't usually have any way to recover HP, like Ampharos
, Lanturn and Lapras. While yes, they do have to give up on Leftovers or whatever they usually run, this does give them a one time use of a recovery move that also happens to fully heal status off your team. It might be more interesting to run than RestTalk. Ampharos and Lanturn however don't really have any Normal type moves to use Normalium Z with (except Hyper Beam) in case it doesn't want/need to run Z-Heal Bell in that particular game, and will mostly prefer Leftovers for defensive sets. Lapras on the other hand has Hyper Voice, which is a bit niche. Other potential users include Lopunny
and Wigglytuff
. These two can opt to use the Normalium Z instead for Return/Hyper Voice respectively, or, in Lopunny's case, Z-Splash.
Z-Refresh works in a similar way, tho when we look at the regular distribution we don't see anything that's particularly useful that might get it that doesn't already have a recovery move or Heal Bell... Until we notice Furfrou
. Furfrou can put Z-Refresh to some good use since it allows it to gain a one time recovery with status cure, but since it's carrying a Normalium Z you can opt to use a one time 160 BP Breakneck Blitz, or even a Swords Dance off of Work Up. Furfrou can put this strategy to great use because it usually has Normal type moves which can make it more unpredictable and interesting.
I'm not going to list the Pokemon that learn Z-Psych Up because that move has a LONG list. Most Normal types that do learn it (but not any other recovery move since otherwise it's more worth it to just run any other item) are too frail to put Z-Psych Up's interesting effect to good use while still being able to fire off STAB Breakneck Blitzes if needed (this list includes Persian, Stantler, Girafarig, Spinda, Delcatty, Purugly, Watchog and Oranguru). There are, however, some other non-Normal type that do much appreciate the recovery and can pull off high powered Breakneck Blitzes if needed, like Dusknoir, however Psych Up's niche effect will probably mean it won't be used much.
Z-Stockpile is interesting in theory because it restores health AND gives you a boost to both defenses. There are a lot of Pokemon that learn this move and I won't cover them all. Komala
and Munchlax
stood out to me, I can see them running this strategy occasionally, with Return to cover that Normalium-Z use if needed (Komala however might prefer Wish imo). Wigglytuff and Lanturn are other possible users of this move since they very much enjoy the recovery, and the extra defense boost can be helpful, though Wigglytuff might prefer Z-Heal Bell imo. Alolan Raticate also gets it, but I don't see that being important in NU.
Z-Spite stood out to me because of the potential of using Ghostinium Z with other Ghost moves. However, after seeing that move's distribution, I can only see some very niche sets from Mismagius/Misdreavus and maybe Weezing and Ninetales. The move itself is basically worthless in NU apart for some niche PP stalling sets (which I don't know why you would run). It's a shame Dusknoir doesn't learn Spite, though, as Pressure meant it could actually put that move to good use. However...
Z-Curse, when used by non-Ghost types, adds another +1 to Attack besides the regular effect. However when used by a Ghost type, Z-Curse restores HP, much like Belly Drum. Dusknoir
, Golurk
, occasionally Mismagius
and, in case they drop, Spiritomb
and Cofagrigus
will very much appreciate this one time move, being bulky Ghosts who have been cursed with no recovery, that is until now. Dusknoir and Golurk in particular love to fire off that one Never-Ending Nightmare from Shadow Punch while very much appreciating the recovery. I think these are probably the Pokemon that will most benefit from Z recovery status moves this gen.
Z-Haze is another move that has some potential because of the combination of (vanilla) Haze's usefulness, Ice typing, and distribution. Aurorus
, Omastar
and, in case it drops, Blastoise
can all run this move and appreciate Icium Z's potential with their Ice moves (Ice Beam mostly). Dusknoir can also use Icium Z with Haze and Ice Punch if it wants to, but I believe it will usually prefer Ghostium Z with Curse.
Z-Mist works a lot like Z-Haze, except Mist obviously isn't as useful. Still, I can see it being used somewhat rarely by Piloswine
, Abomasnow
, Vanilluxe
, Lapras
, Lanturn
and Wishiwashi
. Lapras and Lanturn in particular will prefer Icium Z over Normalium Z (for Heal Bell) since it gives them the option to run a one time powerful Ice move from Ice Beam over a powerful Normal move in Hyper Voice (in the case of Lapras) or Hyper Beam. Wishiwashi can now be used more than once in case it's HP drops to less than 25%, and still has the option to run a powerful Ice move as well if it happens to not want to use Z-Mist. Piloswine obviously appreciates the recovery as well.
Overall, I think Z status moves are the most unpredictable mechanic introduced this generation, but Z recovery moves in particular will have their uses, most notably with Z-Curse Dusknoir and Golurk, Z-Refresh Furfrou, and perhaps others I just listed. We'll have to wait and see.