I've done many paid articles on my blog, but i'm generally pretty wary of writing about projects that are still in development.
I don't want to promote any subpar projects and I have rejected offers in the past because of this.
I think most writers would do the same thing. In fact, it would be really odd if writers accepted any offer that they receive, which in turn can make their blog/content platform to be full of promotions, and then it will be your regular bounty hunter spam.
It's a great idea actually, not only their content gets indexed by Google but if the right keywords about your project are targetted you can have many people searching online landing in your project just go with a blog with good Google page rank, they are respected by Google and anything they write will be landed on the first page of Google.
I wonder how many top crypto writers can land on the first page if the readers use general keywords like "medical breakthrough" and so on. I'd not be surprised if most of the time they find it from forums or social media and not Google search.