The original games will still be there, Nintendo is not coming to your house to remove the memories from your brain and melting the games down. (I think)
If it is Let's Go, you don't have to buy it.
A Game doesn't have to be tailor made for you to be a good game, and other people can enjoy other games, There is no Objectivity when it comes to enjoyment.
Thing is, there's a flaw with this logic:
There are a company, and they need to make money, no matter what. (and have a good image with their audiences too if they care enough)
If they piss enough peoples that it directly affect how much money they could get and make them get less money then they used to make said game , then it could affect their future project quite badly.
Of course, it's Pokemon we're talking about, so it sell like hot breads or whatever the **** you say in English, but peoples are only so tolerant before they notice they're getting dunk on.
It's not a Pokemon only problem mind you, but it's worth noting I say.