Switch: a multi-wave console lifecycle (prediction)

[Louie]

Soundwave said:
From the Q/A briefing following the earnings release:

Barely in the middle of the switch cycle, no change to that view.

— David Gibson (@gibbogame) May 7, 2020

Basically indicates Nintendo sees this as the half way point of the Switch cycle, which probably indicates March 2023 is where they see a successor as of now.

"Barely in the middle of the Switch cycle" is the quote. Which indicates we're not even halfway through the console's lifetime, so late 2023 at the earliest.