Agreeing with the others here with Option 4 being the best option for us right now. Electabuzz is a big menace right now, as it outspeeds every unboosted Pokemon in the metagame, and has great power and decent enough coverage to go along with it as well. It can easily chip away at a team with Volt Switch and clean up late-game, and it forces almost every team to have a Choice Scarf user or something super weird like Chople Berry Piloswine to deal with it. While Chansey would help check special Electabuzz sets, Cross Chop mixed sets would easily start to become more popular to lure in and 2HKO Chansey after Stealth Rock, so it would still be a problem. Now, if Electabuzz gets banned, the speed tier would drop, but Frogadier, the second fastest Pokemon after Electabuzz right now, would just emerge as the fastest Pokemon, and while it does have more checks than Electabuzz, it would still be really hard to fight against. Chansey being in the tier not only helps deal with special Frogadier, but it helps against a majority of other special attackers, like Seadra. While Chansey does check almost every special attacker, it does have ways to be gotten around, like being lured with mixed sets like Cross Chop Magmar or Low Kick Frogadier, or just being beaten by the physical attackers of Middle Cup, of which there are many, including powerful Fighting-types like Monferno and Gurdurr. Chansey also has a problem with entry hazards wearing it down each time it comes in, and with the amount of damage it has to sponge, it can get worn down rather easily, even with reliable recovery in Soft-Boiled. So, that is why I think going with Option 4 (Banning Buzzer and unbanning Chansey) is the best way to go, as it helps balance the metagame a bit while also not adding anything too broken to the mix.