1. someone at exec/board/mgmt-level somewhat detached from product development process sees it and comes in with the "see! this is what it should look like, this looks way better, this guy gets it and he doesn't even work here! you should hire him / do this." which doesn't tend to be received too well from the people doing the actual work, who for right or wrong have all sorts of reasons it doesn't look like that.
if they are forced to bring him in or do it they probably aren't going to like it / him.
2. someone on the team sees it and goes "well, this dude doesn't understand the massive complexities and risks involved in something like this but hey that one piece is not that bad of an idea, let me re-work some stuff", but it doesn't seem like it would help them much to bring him on-board... "uninvited" has a negative connotation for a reason.
of course if could play out very differently, but responses along those lines (if any at all) seem most likely from my experience. it seems like a good approach to rally community support for something, but the community is not the people building the product by definition.