I sometimes dont't like that celebrities advertise a project, they were usually paid to do so, and that does not reflect in the project itself, now if a celebrity advertise on its own, due to actually liking the project, then that is different, but any celebrity will do that, because they have a lot to gain by charging the project itself.
I think indeed the project has already enought competent people already. When i saw the curriculum of the team the first time i was very impressed.
There is no particular need to have anybody who is particularly more famous for one reason or another, imo.