I might add supporting both systems only works to keep sales steady if the sequel system is seem as not worth it or if the sequel system has no BC
Sony keep supporting PS4 with software and third parties are all about cross gen games, but PS4 sales have plummeted. PS5 being full BC and smart delivery are making people go for it ASAP as there is no point buying a PS4 if all PS4 software can run on PS5
The question of whether Nintendo wants or not Switch to keep selling depends more on what they do for Switch 2 than what they do for current Switch
I think Nintendo wanting the same thing to happen (PS5 destroying PS4) is likely because again all big third parties will avoid commitment in Switch 2 until Switch 2 has a userbase big enough to justify their investment (I'm talking about AAA games here, like Monster Hunter Rise)
Nintendo strongly depends on their own games to cover their lack of third party blockbusters. Smaller third party titles and indies that can easily run on both Switch and Switch 2 won't make people buy Switch 2 to play games that don't need performance and graphics improvements in first place
Hence Nintendo will need to artificially kill Switch support so Switch owners will feel the pressure to move on.
