I too would be interested in a return of the Junior.
However, if you want one while your kids are still kids, the recently discontinued Sliverax has a similar guard in the handle. You could also grind off the flipper tab if you want to make it thumbhole opening only.
Occasionally you can find one on the secondary. I got one of these on the secondary for my son. It works really well and it’s pretty safe. My son is 4 years old and already knows how to slice up his fruit with it. It’s a very intuitive design to use for him. Obviously still a two hand open and close for him tho.