Interesting. A bit inconvenient. A whole lotta engineering to do something that n'lock does much more simply. And that n'lock does much more conviently by simply flipping a switch and removing a key, no disassembly of the seat post, no bending over the bike down almost to ground level (very inelegant for a lady), no wondering about the integrity of those hinges... Be surprised if this idea goes anywhere.
On the other hand, much worse cycling ideas have made it to the market: remember offset cranks, oval chainrings, etc, etc? It could get to be a long, long list.