Before this generation I expected 7-8m for the PS5, but this became very improbable quite early on already (read: 2021), because PS5 sales in Japan did not and still do not align with demand by Japanese gamers. Matching the PS4 became possible after a while and now with 2023 being almost over, anything under 10m is unrealistic.
I don't rule out that the PS5 could surpass Wii sales, because the exports of PS5s sold in Japan might continue for another couple of years or perhaps even longer. Predicting PS5 sales in Japan isn't straight-forward because of this big X-factor.
Legend11 correctly predicted that GTA IV will outsell Super Smash Bros. Brawl. I was wrong.