Agree with z on fur coat, zera and to some extent rain
While not having recovery certianly can be a problem, that doesnt stop fur coat inheritors from being a mayor nuisance. Apercian gives quite some utility options such as knock off, toxic, your pivoting move of choice with u turn and parting shot, foul play for obcenly strong attackers, roar for setup and subs, and even swicheroo and hymnosys if you are feeling crazy. Trying to hit it twice after it switches in means it gets to pivot out to something that can threaten you. Trying to setup will get you roared. Not even defensive mons are save due to knock and taunt. It also just so happens that the best special wall in the tier has a tremendous hp, making it a formidable partner and fixes its issue of not having recovery
Almost nothing relevant can wall SFLO Zeraora. FireBoltBeam is all fun and managable until it slots close combat. Now it can 2hko Snorlax. And goodra doesnt enjoy it either. When Zera enters the field, it feels like the world is your oyster, as in any normal team there is nothing that doesnt feel threatened by its coverage moves, if not outright ohko'd. Outspeeding it requieres either scarfs, speed boost, unburden or ninjask, the dedicated lead, so most offensive mons are out of the picture. Only two things that dont take 40% from any of its coverage moves that i can think of are flash fire Spdef Aegislash and physical heatom, and the latter can be thrashed with surf. EDIT: Just remembered it can also use throat chop/earthquake to hit the afromentioned set too. The cherry on top is that Zera can do much more aside from SHLO. Physical sets using mawile for thunder punch, or conkeldurr for guts boosted attacks, the classic pinchurin set with spikes and a obsenely powerful rising voltage, and lead sets too. But none of them can excert as much pressure as Tauros Zeraora. Dragapult might be able to have the meta on his palm too if a mixed set as good as Zera's is found, and i dont think it will take long for that.
It baffles me how weather avoided the nerfhammer while terrain got nerfed. While dealing with rain boosted attacks from one Pokemon is managable, having one rain setter+ 5 mons with swift swim turns the game into a waiting game until its your turn to play. Of course, Toxapex and goodra can do pretty well, but overwhelming them with whatever mon of your choice isnt impossible. Also bringing your own weather makes the machup 110 times easier, as with any free switchin you can thwart the pouring with nice clear skies, which will allow your team to dry up and get a breather, and make the opposing team's chances of 6-0ing you evaporate, as they are forced to stop their onslaught of hydro pumps to bring their rain setter again. Lastly, if rain is deemed in need of a nerf, I'd rather have it be a complex ban like in BW where swift swim+Drizzle is banned, but i doubt that the all-might smoogon policy allows it
Finally, I must argue against the ban of ice scales. Unlike Apercian, Frostmoth's movepool is severely lacking; its utility options being u turn, defog, and stun spore. Similarly, if used with a defensive purpose in mind you become forced to run quiver dance if you do not wish to be as passive as a taunted vanilla shuckle. This lead us to the issues, say, a kyurem, would run into if it tries to use ice scales as a way to set up quiver dances. The second the iron men enter the battlefield any quiver dancing frostmoth inheritor becomes nullified, as the only way for frostmoth to hit steels even neutrally is with a weather ball under sun or rain. And if any steel type with some sort of special bulk can wall it, then they can also use their STABbing moves to reduce these inheritors to rubble. The walls of Iron arent the only ones on their way, common pokemon such as Toxapex, Snorlax, and even AV Goodra can stand on the way of their freezing assaults and do of them whatever they want
Also the real thing holding back regen spam is that there's only one guy who had the time and pacience nessesary to switch around a lot and chip pokemons for 50+ turns. Add 2 Ability clause.