No exact release date for the new program has been announced, but My Nintendo mentions that the change will be coming in early March.
As long as your My Nintendo account is linked to the Switch, 3DS, or Wii U system that you're using to purchase digital software, you will automatically accumulate Gold Points upon purchase.
Players can earn Gold Points by purchasing Nintendo hardware and software, as well as through playing Nintendo apps on their smart devices. I have a gazillion of those from playing Nintendo mobile games, but nothing to buy with them. According to Nintendo, 60% of US Switch owners own Super Mario Odyssey and 55% own The Legend of Zelda: Breath of the Wild.
Meanwhile, the Nintendo U.K. website states that Nintendo Switch users can use Gold Points to partially pay for digital games, too, and use their current eShop balance to cover the rest.
For example, purchasing a £40 title will earn you 200 points, so you can technically save £2 on your next eShop buy. While this seems to be the direction of speculation, Nintendo hasn't definitively set the value of a single Gold Coin. The catch, however, is gold points are going to expire after 12 months, so use them or lose them.
The Gold Points that you earn will only remain valid until the end of the following calendar year.
Stick around for updates on whether this new 5% system for My Nintendo is exactly as it seems.
Of course, you can also continue to redeem your points for existing My Nintendo rewards for Wii U or Nintendo 3DS systems.