Nah, PS5 will sell way beyond. It will outsell PS4 launch aligned this fiscal year, and will keep outselling both launch aligned until the end.
I think it will end closer to the 155M of the PS2 than PS4 and Switch. I think Switch 2 will be released the next fiscal year, causing a big drop in Switch 1 sales, which will be discontinued a year or so later having sold around 140M.
I think PS5, now free of shipment shortages and with the extra popularity that its IP will get with cinema/tv adaptations, mobile games and PC ports, has potential to go 150-160M or even a bit more.
Sony has been increasing the size of their studios to allow them work in more games at the same time, acquired more studios and made their biggest investment ever in securing 2nd party and 3rd party exclusives for PS5, according to Jimbo they plan to have more exclusives this gen that they ever did before. All this took time, meaning that the 2nd half of the PS5 generation will be really busy regarding exclusives.