What if the reason behind the cull is to control the next game's prices for a long time?
Well, Masuda said that one of the intentions behind the cull is to give every pokemon their time to shine. Here is what i think it means.
Imagine that there are exclusive pokemon in every new title of the franchise and they are exclusive for that title. For example Charizard being exclusive to sword and shield and Torterra being exclusive to the sinnoh remakes.
This would mean that everyone that wanted a specific pokémon would have to get that specific game, meaning that there will always be demand for every single game!
Not only would the games keep selling like crazy but everyone would have to keep paying the pokémon home subscription forever.
And since the graphics haven't been getting any significant improvement they would be able to pump as many games with "exclusive" pokémon as they can while investing as little as possible.
This could also be the reason why the uproar didin't change Game Freak's decision, because this is basically their new business model