the latter part just isn't realistic - the only advantage a ground has is dissuading electrics, which aren't really used due to their popularity. So nidoqueen's a bit less powerful meaning you can check it slightly easier early game. Personally I think toise is easy to chip/para and queen literally only needs one free hit and then toise isn't a counter to it next time, or if it gets para'd it's the same game. Literally the only difference will be that it's easier to check and you have a Pokémon that can counter it in the limited sense (compare jolteon countering zapdos and golem countering zapdos. Yes jolt is a counter but in practice it's very limited in that capacity, for obvious reasons). Really I don't think queen around will make that much of a difference - all it means is keeping a couple of possible mons [staryu/blastoise] para-free means you can actually switch in on and force out the nido... except that venomoth already does that (particularly when sleep is not yet burnt). Heck, before a certain point in the game, you don't even want nido to come in because it gives the opponent the sleep advantage. Look, I know there'll be a difference if be ban nidoking for nidoqueen.. but 4U will just become 'nidoqueen tier' (insofar as it's currently 'nidoking tier'). It just becomes a little easier to check/force out, and changes the balance on the values of keeping certain mons status-free a little. It's not the difference between tauros and say persian or kangaskhan, it's the difference between tauros and tauros with 5 less speed and 5 more hp.. yes it's neutered a little (gengar and uhh raichu speed tie no more.. and the irrelevant Electabuzz, Kadabra, Rapidash, Scyther tie) in some ways but in practice it'll not really change the game in that much of a conceivable way. So yes, nidoqueen won't be as dominant as nidoking was, but the difference will be small and not shift the meta very much, without really reducing its effectiveness by all that much. The game will still have the same intense feel to it, the meta will still be as closed, and the weaker nido will still be your breaker and cleaner, it will just be marginally less effective.Well... pretty much agree with what Marco said... 4U is Nidokings Tier... not that it wins games on its own, but as Marco already said, it is both wallbreaker and Sweeper whereas Queen is not that much of a Sweeper mostly due to speed...
Nidoking can take out pretty much every mon on the opposing team that troubles ur own team (including Abra) and still outspeeds a lot so that u might have to go for a speed tie with ur own King to revenge it (or tie with Staryu), which u can obviously lose (and in worst case even die to a crit). One can compare it to Tauros, but I think in this tier it is even better than Tauros in 1U.
While I agree that Queen would likely take his spot, she will not be as dominant due to being actually easier to revenge kill and switch into generally (Blastoise). And thus I believe that it would not just replace it and not be S rank in the new meta (maybe not even A) which leads to players not using it on almost every team, which could definitely lead to more diversity because maybe Electrics are actually used or people think about another Ground instead of Queen (Onix, Graveler?)...