That won’t sink Nintendo. It will only increase their revenue.
People will rebuy the old game again. Some people will refuse to buy the old game. But no sale would be lost. In fact people will be less likely to sell their old consoles, reducing the supply of consoles which will increase demand on the new console.
People always make the assumption that a business will lose by making customers pay for things. It rarely is the case. Netflix banned account sharing, Reddit and Lemmy were full of people claiming this will hurt netflix. Not realising netflix only punished those that don’t give them more money. The people that suffered that ban weren’t buying netflix. The ban increased netflix profit, they also gained more paying customers.