This is as interesting as the first idea. We just went ahead with the "rejected" instead of the "offer" route because I had experienced getting far with interviews at Big Tech and then getting rejected. Felt it would be nice to use this "token" of having advanded to get other opportunities. Might tinker with the offer idea as well, but betting on this for now, esp. now that many Big Tech Cos have hiring freezes.

This would only work for so long. As a company scales up there are going to be legal complexities in justifying and analyzing why a person was hired.

I can definitely see a tiered service where if a person got an offer they would be more sought after by companies.