A+ -> S-
Landorus is very unique in its ranking, and its qualities are the sole reason I see nothing else touching the S tier during generation eight. Clefable has a lot of benefits, including its variety and staying power which allow it to fit multiple roles on bulky offensive and balance teams alike. However, it doesn't match Landorus in terms of consistency and splashability, so I think S rank is a bit of a stretch. But I do think that S- is a very appropriate rank for Clefable, and its recent usage reflects that.
A+ -> A+
I have to disagree with this one. Although the slowtwins have fallen somewhat out of favor for other bulky water-types, Urshifu has remained a relevant offensive mainstay in the metagame. Urshifu's Taunt Protective Pads set is certainly not a gimmick, and has seen repeated competitive use alongside partners like Choice Scarf Future Sight Tapu Lele to help it break down physically defensive targets like Toxapex and avoid contact effects which can otherwise limit its offensive potential. The offensive presence and continued momentum Urshifu offers on many teams makes it more than appropriate for A+ in my eyes.
A- -> A-
I somewhat agree with this one. Tyranitar's success on bulky offense, balance, and sand teams alike is due in part because of its Choice Band set which generates a lot of offensive pressure and facilitates partners like Excadrill and the occasional Dracozolt. Tyranitar's defensive sets also threaten most defoggers and apply Stealth Rock while also compressing a ghost-type resistance, which greatly frees building constraints for some teams. Its Sand Stream ability allows it to check weather archetypes like Hyper Offense, Rain, Hail, and Sun, which is invaluable at the moment. However, it can be difficult to fit because of how support specific it is, which makes it less splashable. Overall I can definitely understand why it might have some justifiable qualities, but it still feels short of A.
A- -> B+
This one I agree with. Zeraora feels very underwhelming at the moment, with the ubiquity of ground-types like Landorus, Garchomp and Hippowdon, resistances like Buzzwole and Tapu Koko, and the general abundance of fast revenge killers and contact effects, Zeraora can't catch a break. Zeraora's Bulk Up set is the most reliable, where its pivot and Choice Band sets are more inconsistent and prediction reliant. In its current state B+ feels more appropriate for Zeraora.
B- -> B+
Another one I agree with. Blaziken is a very threatening sweeper that can be hard to account for in the builder because of its overwhelming nature and choice variety which brutalizes its checks. The recent rise Dragonite, Rotom-W, Gastrodon, Volcanion, Rillaboom and Ninetales-A, and the trend of Taunt Protective Pads Urshifu, have both indirectly benefited Blaziken heavily by restricting archetype specific checks. Blaziken is certainly worthy of B+ at the moment.
C -> C-
Mach Punch go brrr. When ghost-type or resistance, Mach Punch no go brrr. Conkeldurr checks popular, Conkeldurr hard to build with, Conkeldurr easily overwhelmed. Conkeldurr go C-.