Looks like they're doing their japanese IME releases on 1st of October instead of the 1st of April. Half a year later. The previous releases are all shown in that repo's readme.
Do google do april fools pranks anymore? I forget if they resumed after 2020.
Fingers are not meant to have good strength or dexterity that direction. It would be very tiring, difficult and I'd assume would be easy to end up with RSI issues. Not to mention it's a bit hard to imagine what the device would look like.