Is there not an open source hardware project to revive these? I was scanning the comments assuming there must be someone doing that. No?

This seems like a project that, if it were completely untethered from commercial desires, would be incredible for kids and adults to play with. I can imagine tamagotchis that could wander about the house (like a remora fish on a shark), finding random bluetooth connections to feed upon, sending strange messages to watches and iPads. All kinds of fun ideas come to mind.