I believe doing a pilot makes practical sense for a number of reasons. Just the sheer scale of trying to onboard folks and communicate and educate individuals about what this means would be untenable.
In terms of conducting a pilot, however, I would urge that it be on an opt-in basis, for the purpose of developing something with the intention of iterating, so ensuring that you're not trying to bite off everything and be perfect, but just beginning that engagement.
It would also be a really practical way to start introducing the concept, especially if it's set out so it's an optional activity where the folks in charge of developing the solutions would take that information. Having that public engagement would be an interesting model, but certainly knowing and understanding going in that it would be an iterative process would be important.
I believe that's really what privacy by design principles are really about. It's about understanding what the requirements are up front, then all along the way it's going back and checking whether we met those initial requirements and met that intent. Then it's taking that feedback and iterating again and again.