They will surpass it easily.
"The latest official global sales figures, shared by Nintendo back in May, show that Switch had sold 84.59 million units worldwide as of March 31st 2021. That number will naturally have risen quite substantially since then, moving the Switch ever closer to the Wii's mighty lifetime sales total of 101.63 million units".
That is a 4 years console sale. The ps4 had to sell 116m in 8 years. It had 3 upgrades, which boosted its sales. The switch took 4 years to hit 84.5m with minimum hardware upgrades.
Unless Nintendo wants to do new hardware, the switch will hit 120m easily.
The thing is consoles have a sales curve: they start and end with lower sales, and have their sales yearly peak during mid gen, around aprox its 4th year.
What we saw in the recent year or two aprox. was Switch's sales peak that all consoles have, but in this case also extra boosted by the covid related boost the other digital entertainment and internet companies also experienced. Boost that cought the other consoles in the lower parts of their sales cycle: when they are ending or when they are starting, so the boost was smaller for them. And on top of that they were also affected by the chips shortage.
What I mean is that we shouldn't expect to continue see Switch with crazy sales numbers all the upcoming years, but instead will start slowly decreasing soon and some time later to decrease faster.
In addition to this, Sony home consoles keep in the market for over 10 years, can be there for a dozen years. As an example, we saw Jim Ryan mentioning in the 'we believe in generations' interview that they will continue supporting PS4 for at least 2 or 3 years after PS5 release because there's still a huge monthly active userbase on PS4 (over 80M MAU as of now) and will continue for a while there even if they continue selling PS5s at gaming history record levels.
Meanwhile Nintendo consoles have a shorter life cycle, of around 5-6 years for most home consoles and for 8-9 years for portables and Wii. So I think we expect Switch to last until 2022-2023 or to 2025-2026, and its next gen succesor to be released a year or so before.
So I think that even if Switch as of now ahead of PS2 and PS4 in launch aligned sales, I think that in the very long run will end behind them because Sony consoles have a longer tail. As an example, PS4 will turn 8 years old soon and early next year or so will get games like Horizon 2, God of War Ragnarok or Gran Turismo 7 plus many other top selling multi or exclusive crossgen games.