siebensus4 on 19 February 2024
The Switch successor will be the first gen 10 console. Wii U and Switch don't belong to the same generation, because Switch is Wii U's successor.
The third generation was also only 4 years long (1983 - 1987) and we haven't seen a successor from the same company which belongs to the same generation in the whole history of consoles. Not even Sega Saturn and Dreamcast belong to the same generation, although Saturn's life span was even shorter than the one of Wii U.
It's a bit unlucky though that Wii U was released one year before PS4 / Xbox One and got replaced that fast.
