If Sony wants to reverse this trend and really be competitive against Nintendo in Japan, it has to start in house.
There is no " reverse" in any way in Japan. Sony did everything and a litte bit more what they could in Japan - Death Stranding, Ghost of Tsushima, Nioh,Bloodborne, Gravity Rush,VR,Nier, tons of other JP games. Japan is done with classic home consoles, period.
Other JP publishers shall port their games to the Switch as well, but there are 2 ifs - sales, what is not great for 3rd party on Switch, and optimalization cost.