Could be, but gamers found a home for DQ in Nintendo consoles. In general, I haven't seen FF really make a big difference in the success of PS in japan like it once did.
I personally wouldn't bet too much on SE. Rather if I were Sony, I would get MH exclusive again, among other franchises that are popular in Japan.
MonHun did a lot for PS4 in Japan and for a while I thought PS4 might finally look better than PS3. But the boost was temporary. But the MonHun boost clearly shows what the PS5 needs to be a more successful console in the japanese market: more of the japanese game franchises.