Give me one example of a flashback that’s incorrect and changed that’s apparently just not the writers making a mistake, when something wrong with the memory isn’t the whole plot of what’s going on.
Look i get that they might be ‘hiding’ it and that the form probably still exist, i didn’t say otherwise, but it doesn’t change the fact that they’ve done it in the most idiotic way possible. Like i don’t even get why anyone would even try to defend such a dumb decision when they could’ve easily done it in a way that doesn’t cause this problem while still achieving the same result.
Serena had two flashback of Ash saying "Don't give till the end" but the way Ash shows his hand is different.
This is XY006:
This is XY007:
Both are meant to be the exact same moment, but drawn in different ways rather than being reused animation. And back to back no less. This tells us that flashbacks are alterable and may not tell the full story. What we do know that is Journeys doesn't make continuity errors without reason. Given the extreme lengths they went to hide Serena (seriously, they only showed Lisia and Wallace in the opening despite the fact they are not as prominent in the actual episode, didn't show who actually owns Sylveon, and went out of their way to ensure that Serena is not mentioned in Ash's reunion with the Lemon Siblings even though the next episode Wallace mentioning May), it stands to reason that Greninja will be coming back.
All things considered, Ash-Greninja is locked away forever in Gen VII, so showing a form that can't be used in the main games anymore is understandable. At least Mega Evolutions and Z-Moves are fair game in the anime because it'd be rather hard to pretend those don't exist in a worldwide(?) tournament.
(What's not understandable is the fact that they had to re-do that specific flashback shot of a bunch of other ones.)
Hard to pretend? You can't use Mega Evolution at all in Generation VIII. Not even for DP remakes and Legends Arceus. And you can't use Z-Moves either. What Ash is doing right now is fundamentally impossible for a newcomer to do unless they got an old copy of XY or Omega Ruby and Alpha Sapphire. Not to mention that Lisia showed up to promote contests despite the fact Lisia doesn't appear beyond Omega Ruby and Alpha Sapphire years ago.
But that would be even more bad writing on their part. Greninjas stuck in Kalos for a reason, and the vines were brought back for a reason.
If they could just erase them with a thought when writing it, then it would call into question even more on why Greninja had to stay.
That's not a fact. That's an opinion. The vines only exist to keep Greninja off of Ash's team, and it's always implied to be a temporary problem as a result of Team Flare's actions.
It's no different from Bulbasaur suddenly being Oaked because apparently Bulbasaur is the only Pokémon able to keep the peace amongst the Pokémon there. Or Charizard being left to Charrific Valley to become stronger. Or Goodra left at the Marshlands to protect it. It doesn't matter in the long run because when Ash decides he wants his Pokémon back, they will come back to his team.
And to paraphrase Stan Lee, everything is at the whim of the writer's wishes. Want Greninja back? Get rid of the vines. Worry that Greninja becomes part of the team? Put him in Oak's Lab.