[The Chaos Entity]

As always, you’re overanalysing again. They used Zero-One probably because he was the first Reiwa Rider, and it likely has nothing to do with ‘Touma being confused because Ikki used the Kajiki ViStamp to look like Sabre’, as that plot development has already happened - in the Fateful Sengoku Movie Battle, they had Kouta use Wizard Arms in front of Haruto with no problem (and even had Kosuke lampshade it).

Furthermore, while the lack of any connection between the Heisei Riders and their ViStamps is likely caused, in part, by the fact that a lot of them share similar animal themes, it is highly unlikely that they chose not to do solely insects ‘because Kabuto already had’, since Revice is the fourth time in the last eleven years that ‘animals’ have been the gimmick theme, after OOO, Build, and Zero-One - and, even more egregiously, the third time we’ve done ‘theme 1 + unrelated theme 2 = new form’ in the last twelve years, after W and Build. It’s also the third time we’ve had ‘Legend Riders’ as the theme in the last twelve years, for that matter - after Decade and Zi-O.
All this to say, of course, that and Bandai aren’t concerned about redundancy as long as it sells…and based on the fact that they’re reusing ‘animals’ this soon after Zero-One, I’d say they’re quite confident that either it will sell, or the Legend Rider element will draw people in anyway. They chose animals that they thought would sell, and paired them with Riders they thought would sell. It really is that simple.