The announcement highlighted significant upgrades to Rivian’s flagship models such as updated batteries, redesigned components, and more efficient drive units.
The new keyless entry feature supports various devices including iPhone, Apple Watch, and select Google Pixel models. Rivian stated, "Rivian owners can use car keys in Apple Wallet on iPhone and Apple Watch, or with select Google Pixel devices, to seamlessly unlock and start up their vehicles, and even share keys digitally with family and friends."
Rivian says that it will share more details when keyless entry arrives later this Summer. Its unclear if the same functionality will be available on existing Rivian vehicles, but it sounds entirely possible.
Source: 9to5google