That is, I understand that generosity is not planned? After all, I have not found any information!
Most likely there will be no generosity. They will probably make a good PR campaign.
This will probably be the right decision if you refuse to bounty. It is better to do advertising for example on television or radio, more people will learn about the project.
Or you can even go out into the real world and post ads on the street and attract graffiti creators and use billboards
Such advertising will not be very effective if you make posters on the street, but at the expense of graffiti is an interesting idea, on the one hand it is original