I voted major improvement BC with $1-$10 upgrades.
Nintendo giving free upgrades universally or even as the standard is even more unlikely than boosted performance. Nintendo charges $60 for enhanced Wii U ports for crying out loud.
I don't think the boost will be universal like turning on boost mode on PS5. Nintendo software and third-party game upticks in performance for BC games will almost entirely be at the mercy of the devs in a free update. Unpatched games will probably have marginally better load times and a trifle better resolution and frame rate just from the better hardware without an active boost or update.
The Zelda games and Xenoblade Chronicles series will get updates for sure from Nintendo.
Lifetime Sales Predictions
Switch: 156 million (was 73, then 96, then 113 million, then 125 million, then 144 million, then 151 million)
PS5: 115 million (was 105 million) Xbox Series S/X: 48 million (was 60 million, then 67 million, then 57 million)
PS4: 120 mil (was 100 then 130 million, then 122 million) Xbox One: 51 mil (was 50 then 55 mil)
3DS: 75.5 mil (was 73, then 77 million)
"Let go your earthly tether, enter the void, empty and become wind." - Guru Laghima
