So the first teaser trailer has been released for *takes a large breath* 'Kamen Rider Reiwa The First Generation!' It very prominently shows a new form for Zero-One.
This (zero) one
And again, on the right, alongside yet Another Zero-One!
It appears that one last Another Rider, Another Zero-One, escaped Zi-O's rewriting of time. As per the usual rules for Zi-O, only one version of a Rider's powers can exist at any one time. As such, Aruto finds that he can't authorise the Rising Hopper ProgRise Key and become Zero-One.
Somehow, Aruto will obtain one of MetsubouJinrai.net's ForceRiser belts and will use that to transform instead, becoming what is apparently called Kamen Rider 001 (Zero-Zero-One).
It looks like this suit (like many one-shot Rider suits nowadays) reuses many pre-existing suit elements; The upper thigh straps and upper chest armour pieces look like those found on both the Jin and Horobi suits, while the knee pads, shin guards and boots look like recolours of the same pieces on the Blood Stalk suit (and those shoulder pads look very round like Zi-O's).