It is nice to know that the Apple Maps team is getting serious about mapping Japanese data themselves. Most of the problems with Apple Maps Japan to date have been caused by 3rd rate 3rd party data suppliers so Apple collecting their own map data is a start towards a better map product for Japanese customers.
There are some notably omissions in the data collection startup list: only 20 of the 23 Tokyo wards are covered. Suginami-ku, Setagaya-ku and Nerima-ku are huge missing pieces along with the rest of the populous west Tokyo Chou line area (Mitaka, Tachikawa, etc.). Suginami-ku is one of the most important Tokyo districts, perhaps the most: whatever political party wins an election in Suginami wins Japan.
There are other big Apple Maps services that are missing in Japan: Indoor Maps were promised back at WWDC17 but have yet to appear, Traffic, Lane Guidance and Speed Limits are AWOL. Most of these services have been offered in Yahoo Japan Maps and Google Maps in Japan for years.
Even without their own data, Apple Maps Japan has made, (very) slow progress fixing some major data errors and holes. The Great Shibu Hot Spring Data Cutoff for example is finally fixed. This is how it looked 2 years ago:
This is how it looks today:
Today it looks like this:
I have not checked all of my Apple Maps Japan error inventory but I think progress is being made. Now if Apple would only dump the horrible Justin O’Beirne era cartography design that dates back to 2012 and create something new, I might even get excited again.