I doubt we are going to see the RK3566 in PinePhones in 2021. That sounds more like a 2022 thing to me – unless getting proper mainline Linux support is going to land extraordinarily fast for that new SoC.

Knowing Pine64 I think they might provide upgrade boards unless it turns out that revising other aspects of the PinePhone hardware (e.g. screen, camera, battery) can be revised and improved cheaply so that this would not make sense economically.