I've seen those advertised for a while (not locally of course).
I'm pretty sure it's just a company buying raw LG panels and doing their own enclosure around it.
What would concern me is the quality of the panel (and likely lack of meaningful warranty).
A lot of times these sorts of products are using sub Apple/LG grade panels (rejects that didn't make it into a normal LG Ultrafine).
The dearth of quality 5K monitors is probably why this company is seizing on an opportunity.
The last standalone Apple display was only 2K and discontinued in 2016.
Today, 4K is the norm and even 4.5K on the consumer targeted iMac.
I just hope Apple might want to address the millions of Mac mini, MBA, and MBP owners who have limited options to connect a RETINA level display to.