Because I have a hunch that when BW is over, as much as can be 'erased' about it will be. Make all those horrible, boring Unova Pokemon who have no development disappear.
Imagine the hell that would break loose if Palpitoad or Oshawott took up an appearance that Buizel could have gotten in Kalos.
Boring? personality wise, this pokemon have the best personalities since Johto.
I doubt Buizel is more popular than Oshawott in Japan, I seriously do and by what I mean is its not even close and I love both of them, Buizel is one of my favourite 4gen pokemon(ingame and anime, favourite in the anime was Gliscor then him) and even I don't believe that.
I don't believe anyone would be annoyed that Oshawott(unless it was permanent I can see people whining) or Palpitoad appear, people are still wishing for Palpitoad to appear, heck people are always talking about KINGLER apearing again, it was the only pokemon last league that wasn't either mentioned or appeared himself.
I don't see why, Snivy, Pignite, Oshawott, Krokoodile, Scraggy atleast wont be used again, plus Leavanny, how is any of this pokemon boring? they all had funny/cool moments and have shown their personalities.
Noctowl and Swellow appeared again, Unfezant can appear also.
Kingler, Corpish appeared again(Corpish didn't battle though) Palpitoad as a chance, or gets Kingler'ed.
Torkoal, Donphan and other non starters appeared again, so Boldore, Leavanny appearing is the same.
Its not like Satoshi only uses his evolved pokemon/supposed strongest by the fandom, he used Quilava instead of an evolved pokemon against Naoshi(event though Quilava is strong, but Pignite is at the same level atleast), he used Gible against Takuto when he could have used something else, same with Torkoal he could have used Snorlax.
I don't think we'll see Dawn again. If the writers want to showcase a Piplup again they'll have a new one show up, like they seemingly always do with old pokemon they want to advertise again.
Yeah its toys are still selling, so even if he is out of the anime, they probably don't need to bring him back, if it stops selling.
I honestly believe the Unova Pokemon will get the Johto Pokemon treatment. Maybe Krokorok and Oshawott will return, but the rest will be mostly forgotten.
What is Johto treatment, coming back in the Sinnoh league and 4 of 7 Johto pokemon appearing again and havinga good showing? well thats great then.
Noctowl beating LickyLicky
Heracross beating Kricketune
Cyndaquil coming back evolving and drawing with Armaldo
Heracross again in Darkrai battle
Donphan jobbing because it had a good showing in BF.
So if that means,
Unfezant beats a strong pokemon
Heracross beats a strong pokemon
Pignite/Snivy/Oshawot evolve and draw/beat a strong pokemon
Krokoodile jobbing a battle or possible getting a win(because it wouldn't have BF like Donphan)
I would be absolutelly fine with "Johto treatment".