Sony has always followed a strict naming policy and they intend to follow this as they have trademarked the names PS6 to PS10 which is recognized worldwide
Sony has been pretty consistent with the names of its consoles and has followed the succession trend and recently they filed a patent for PS6, PS7, PS8, PS9, and PS10 in Japan.
Though this does not specifically mean a lot as the developed of the PS5 is still going on, it does give a hint as to what the future consoles might be named as.
The PS sign and logo as been iconic for Sony and its fans all over the world, starting from the first PlayStation console which was released in 1994.
This may be not more than just a trend that has followed but it has become synonymous with Sony.
Sony has been registering the naming rights of its future console far before the release of its product, which instills faith that the people in Sony truly stick by their ideas.
The PlayStation 5 will certainly be a massive upgrade over the PlayStation 4, though funnily enough, the trademarks for these consoles was registered way before.
The PS4 was trademarked in 2006 and released in 2013, while the PS5 was trademarked in 2006 and will be releasing late 2020.
This is a clear indication that Sony intends to name its future consoles in succession of the naming trend.
It just remains to be seen, how long do we have to wait for the future console releases.