Japan Patent Office (JPO) previously announced the plan to lauch the new patent publication system in April 2022. According to their announcement, it loos like that there is no chage to the timelie of lauch of this system.
When it comes to patent filing, the publication timing is chaged from weekly basis to daily basis. For now, patent applications are published weekly, which means that they are published later than the scheduled publication date, 18 months from earliest filing date. Patent practitioners sometimes utilize this lag between the scheduled publication date and the actual publication date of the gazette when their last-minute applications are just in time before publication. From January 2022, the publication will be daily in principle, so there is a possibility that this kind of lag would no longer be available.
The next point to keep in mind when conducting a patent search is to "discontinue re-publication patents that are not required by law." Even if PCT applications in Japanese are entered into Japan, there is no obligation under the Patent Law to prepare another public bulletin in Japan in addition to the PCT publications. However, currently, the JPO voluntarily prepares a gazette-like version of a re-published patent for such PCT applications in Japanese. As a result, patent practitioners have been able to search for PCT applications in Japanese that have been entered into to Japan in J-PlatPat, However, we will need to deal with this in the future since the J-PlatPat cannot search such patents after the launch of this new system.