We've since come across a document from Apple that indicates users will be able to enable High Power Mode in System Preferences on a 16-inch MacBook Pro with an M1 Max chip running macOS Monterey.
It's still unclear exactly how High Power Mode will function, but we should get a closer look at the feature next week when reviews of the new MacBook Pro models are shared.Apple only confirmed High Power Mode being available on 16-inch MacBook Pro models with an M1 Max chip, so we presume the feature is not available on any 14-inch MacBook Pro models or any models configured with the M1 Pro chip.