Sad to see someone’s small business close, but these products are in a difficult position of being both extremely niche and very simple. Someone went to some effort to source a nice dongle enclosure and do some printing on it, but beyond that the hardware is something that anyone with a little PCB experience could replicate it in a day. I wouldn’t be surprised if these were just sourced from a generic manufacturer in China and they asked for custom printing.
If there’s demand this would be a good project for someone to make and have ready to build PCBs you could order from OSH Park or even a fully project that you could have JLC build and populate.
This company and product line launched nearly 20 years ago (2007) and doesn’t seem to have changed much since. That’s quite a long time for something like this. If the owners had wanted the business to continue (perhaps they didn’t), some diversification could have achieved that relatively easily.
I have a tiny business that makes a gadget for musicians: Think something like an effects pedal. I publish my schematics, have shared PCB files, and even offer to give you some of the parts that are hard to get. A few people have built their own, and share their results in web forum threads about my product.
Very few people have taken the bait. I think we techies over-estimate the ability and inclination of people to make something. Even most programmers don’t want to solder. They may still be technically inclined, but want to be involved at a higher level: Buying the basic stuff and using it as a basis for even more elaborate things.