We adopted Hushabye Lady from New Vocations a few years ago. My memory is they don't want you to sell for a year and want photo updates from you for a few months. I think this is done to protect the horse not to limit the new home. Lady was exactly what we expected from their description, nothing but good things to say about them from our standpoint.
I thought the Chronicle had done an article on New Vocations but I can't find it. I believe they are actually taking the horses to their facilities and giving them a down period and doing some retraining for putting them up for adopt/sale. In the article I read they did this to ensure that they weren't putting "bad" citizens out there that wouldn't work out and end up in worse places or putting horses in incompatible situations. This model definitely allows them to make sure horses look their best for their photo shoots and videos rather than trying to get this info in the midst of a busy track or farm.