I love that this is a project. Heck, I’d sign up myself for the Boston/New England beat if I had more confidence in my portraiture skills. Never really considered the only thing holding back better portraits on Wikipedia was the need for a photographer willing to sacrifice the revenue on one shot for a greater cause.
Greater cause in the general sense of contributing to the world's largest repository of free information, and waiving rights to profit off of your work so others can benefit from it.
And yes, frustratingly this includes celebrities. These are people of outsized impact and/or import in society, and they need to be identifiable so that they can be held accountable.
I agree with your assessment of greater cause and free information, but in this case, the issue appears that the photos are not the most flattering. Look at the examples at the top of the article. Leo is simply looking down and not at the camera. I guess you could argue the Scott Baio is a picture that should be upgraded, but as mentioned in thread, his PR people could easily correct that.
