Oh boy, discussion points! Here's my thoughts on these.
A ---> A-: Disagree
Underestimating Gengar is a VERY bad thing to do. Specs Gengar is a terrifying attacker with incredible coverage and an amazing speed tier, forcing people to make decisive switches and even sacks repeatedly over the course of the match every time it comes in. There's tons of great things it can partner up with, forming cores that net this thing kill after kill, to the point where just its presence causes people to gamble and overthink. Sure, I may be overstating it a bit, but this thing has won me game after game, and there's no reason it should be in A-. It's great matchups against OU's best megas (namely Medicham) only help it.
A ---> A-: Disagree
Keldeo is in a UU league of it's own, how it got down there is anybody's guess. Secret Sword in and of itself is a wonderful pressuring tool, harassing SpDef switch ins like Rotom and Chansey. It's coverage movepool, while sorta crappy, gets the job done, and it can put out enough power when backed by an item that it definitely has as much impact as Pokemon like Mega Mawile, Tapu Koko, and Gengar, all other A rank Mons. A- is simply not doing it enough justice.
A- ---> B+: Agree
Heracross was awesome when it first came out, primarily becuase it ruined BP teams and nobody knew what to counter it with, since nobody ran Flying type moves. However, the BP ban and resurgence of Mega Pinsir and SS Lando-T have been a serious pain for this thing, making it have to be played much more warily than it wants to be. That base 75 Speed isn't doing it any favors, either.
B ---> B+: Disagree
I don't see any reason Mimikyu should be B+. It is COMPLETELY walled by OU's premier physical walls unless it's at +6 (and who lets it get there anyways.) Tapu Lele dances on this thing's grave as easy fodder if its Disguise is down (which isn't hard to accomplish), and it's only half decent speed and attack when unboosted don't help it at all. BP being gone and Mega Heracross's decreased viability don't help this thing at all, and even hurt it a little, as bringing it in against the start of a BP team usually meant you could get more Dances in. That's not the case anymore, though, so nothing merits a rise for it.
B ---> B+: Agree
(See my earlier post.) Weavile is great. A Knock Off-using revenge killer with ample enough coverage to keep people guessing and in fear until it's movepool is revealed. This thing absolutely merits a rise, as even the thought of Knock Off sends Lele and Latios running.
I can't really comment on Reuniclus, never actually used one. Ever.

Underestimating Gengar is a VERY bad thing to do. Specs Gengar is a terrifying attacker with incredible coverage and an amazing speed tier, forcing people to make decisive switches and even sacks repeatedly over the course of the match every time it comes in. There's tons of great things it can partner up with, forming cores that net this thing kill after kill, to the point where just its presence causes people to gamble and overthink. Sure, I may be overstating it a bit, but this thing has won me game after game, and there's no reason it should be in A-. It's great matchups against OU's best megas (namely Medicham) only help it.

Keldeo is in a UU league of it's own, how it got down there is anybody's guess. Secret Sword in and of itself is a wonderful pressuring tool, harassing SpDef switch ins like Rotom and Chansey. It's coverage movepool, while sorta crappy, gets the job done, and it can put out enough power when backed by an item that it definitely has as much impact as Pokemon like Mega Mawile, Tapu Koko, and Gengar, all other A rank Mons. A- is simply not doing it enough justice.

Heracross was awesome when it first came out, primarily becuase it ruined BP teams and nobody knew what to counter it with, since nobody ran Flying type moves. However, the BP ban and resurgence of Mega Pinsir and SS Lando-T have been a serious pain for this thing, making it have to be played much more warily than it wants to be. That base 75 Speed isn't doing it any favors, either.

I don't see any reason Mimikyu should be B+. It is COMPLETELY walled by OU's premier physical walls unless it's at +6 (and who lets it get there anyways.) Tapu Lele dances on this thing's grave as easy fodder if its Disguise is down (which isn't hard to accomplish), and it's only half decent speed and attack when unboosted don't help it at all. BP being gone and Mega Heracross's decreased viability don't help this thing at all, and even hurt it a little, as bringing it in against the start of a BP team usually meant you could get more Dances in. That's not the case anymore, though, so nothing merits a rise for it.

(See my earlier post.) Weavile is great. A Knock Off-using revenge killer with ample enough coverage to keep people guessing and in fear until it's movepool is revealed. This thing absolutely merits a rise, as even the thought of Knock Off sends Lele and Latios running.
I can't really comment on Reuniclus, never actually used one. Ever.