The correct answer is we don't know.
That said, it's typical the market leader tends to do significantly worse the following generation. Was true of the PS2 to PS3, Wii and 360 to XBox One and Wii U. You can speculate the reason why but I believe it's because the loser have a better idea of what went wrong where the winners tend to rest on their laurels and make stupid decisions. Sony has had quite a few blunders with cross-play, censorship, their Nintendo Direct thing, and the fact these games are announced years in advance. My expectation is they'll do worse but you really can't tell much without seeing the console and the games.
Known as Smashchu in a former life