Keen eyed fans may have seen a small, white Matrix-shaped device in recent JP hobby magazine scans.
A few early details were suggesting it to be involved in an upcoming Japanese TFPrime promotion, and now that it has been seen setup in a store (fully coloured now too), images and details can now be seen here.

So basically, it is part of an endcap display in stores that have an aisle set aside for Transformers toys and product display. The Matrix device is a TV screen, running info videos of Transformers, with 8 character images on the Matrix Handles.
Those 8 characters are original "Primes", named after areas/zones/districts of Japan (I don't think they will be anything in Canon though, just named as Primes only for this promotion).

Most of the character art for these Primes use existing (recognisable) characters, with a mix of parts or heads (and in some odd colours, that also reflect something of that districts).

Akiba Prime for the district of Akihabara (white TFPrime Arcee?)
Kawasaki Prime for the city of Kawasaki (blue Gen1 Jazz)
Tachikawa Prime for the city of Tachikawa (dark green Movie Springer?)
Umeda Prime for the district of Umeda (yellow Movie Ratchet)
Nagoya Prime for the city of Nagoya (black/gold Movie Ironhide)
Saitama Prime for district of Saitama (white/rainbow Legends Movie Bbee)
Ginza Prime for district of Ginza (white/gold Movie Optimus)
Mito Prime for the city of Mito (gold/purple Gen1 Hound)

Toys of each of these are possible, especially since they all seem to use (cheap) Legends/Legion toy designs instead of their on-screen designs or even official artwork, but nothing has been mentioned yet.