First off I'll repeat some noms I still feel need to pass through:
Now, for the further scourging of the B ranks (meaning B+ and B- too)
Salamence to C+ - No reason to use this over Gyrados rn sans the 100 base speed - insignificant as it's gonna get revenged with the >100 scarfers anyways. It has a terrible defensive typing and not enough bulk, making it very hard to set up in this current meta.
Bisharp to B - Webs is dying and this was at its best on webs. Outside of it, it loses to bulky steels and it loses to rain. It also loses to the rising Tapu Koko.
Togekiss to C+ - Honestly, it's not very good right now. Its only niche is a stallbreaker, but it loses to Chansey, Clefable and even Zapdos without significant hax on its favor. Air Slash is a weak STAB move and there are plenty of flying resists or mons just flat-out capable of taking them on stall. I don't see this, a failing stallbreaker, as good as Ninetales-A, the heart of AV, Smeargle, the heart of the still-ok SW, Nihilego, a decent scarfer, Mega Gardevoir, a very strong breaker or Muk-A, a great Pursuit trapper and special tank. I also have no problem seeing this on the level of Mega Aero, Cofagrigus or Mega Chomp.
On a final note, I'd like to second Gastrodon to B rank because this thing truly walls rain.
And now it's time for the C ranks:
Dragonite to C - As a DDer it's just too easily neutered. You have >100 scarfers everywhere that'll outspeed it at +1. While it can get to +2 with its bulk, it needs SR off the field - not easy to do - and since it doesn't run Roost, it can be pressured and be prevented from setting up twice. At +1 it's just rather underwhelming. The opportunity cost of the Z-move slot is also too great. I consider Salamence, a mon I believe belongs in C+ and is a DDer, much better at its job with the potential to snowball out of control. I also consider Cofagrigus and Scolipede better sweepers. This doesn't seem out of place with Buzzwole, Cresselia, and Thundurus-Therian rn.
Gyarados-Mega to C - This just sucks. At +1 it can't really sweep and it's never getting to +2 with that god-awful defensive typing. The opportunity cost is rising with new megas being released. There's also an opp. cost compared to regular Gyarados, which honestly is just a much better sweeper. Honestly I'm even considering C-.
Breloom to UR - I haven't seen it at all this gen and it's not hard to see why. Terrible defensive typing, terrible bulk, terrible speed with Mach Punch being negated by Psychic Terrain, and Spore losing out with Tangrowth and Electric/Misty terrain everywhere. Rain outspeeds and kills, it can't really do much to bulky steels and double defog stall doesn't have issues at all. No reason to use.
Magneton to UR - With Magnezone falling off, I don't see why this is here. IK it's used as a choice scarfer that has an ok speed tier to beat stuff like gren but honestly it's supposed to trap steels and when it can't do that well enough anymore it's time for it to get UR.
Kabutops to UR - Mega Swampert just about 100% outclasses it.
The A ranks are pretty stable rn, no need to discuss changes there except for my previous two noms. I hate to seem rude or anything of the sort, but may I ask why Zapdos and Tyranitar weren't raised, particularly Tyranitar?
EDITS:
Mega Swampert is pretty much THE premier swift swim sweeper on rain teams for its defensive utility, sheer power and wide coverage. Honestly, Ground > Rock both offensively and defensively, and Mega Swampert's insane bulk more than makes up for both the mega slot and the somewhat lower speed. In addition, Offensive Z-Fly Lando is a great fit on rain teams and by using the Z-Move on Kabutops you're giving it up. Honestly I'd rather have those two than Kabutops.
Bisharp is gonna take me a long time to write up so I'll fully flesh it out later, but tl;dr rain's no good for it, Duggy + Zard Y is absolutely terrible for it and it alone could drop it to B, Koko beats it, bulky steels beat it. All of these are rising, and Bisharp just reacts terribly to these.
Gyarados-Mega has virtually no utility vs offense, as it's just too slow and has too poor a defensive typing. Against stall, it ails vs Skarmory (3hkoed but can roost away and phase out if you don't have Taunt), and Sash Dugtrio can use Reversal and OHKO. Honestly, I don't see it on the level of Mega Aero, which outspeeds almost every scarfer and can just straight-up sweep offensive teams late game, Mega Garchomp whose SD set murders any form of stall far better than Mega Gyara ever could, Manaphy which is a better balance breaker, or Scolipede, which uses Speed Boost to circumvent any revenge killers.
As for what got worse for it, it's the new stall. Double Defog just shits on it. If Zapdos gets in free and pulls off a discharge, Mega Gyara is going to take significant damage. If it's paralyzed, game over. Skarm, as I said, beats it, along with Duggy. Also, it can't break through Ferrothorn, anything offensive that's rising sans rain is bad for it. It's that bad vs offense. The release of Lopunny and Gallade-Mega hurt it a lot. Lopunny still outspeeds at +1 and kills, whereas Gallade provides competition by being better vs balance while still not losing to stall given that mega sableye is taken out for it.