Perhaps not the most elegant way of putting it. Many professional sportsmen (and celebrities for that matter) can not string a sentence together to save themselves.
Ghost writers are sometimes used to "assist" them in that task, to produce something that is actually readible for the market.
The marketability of a Ghost writer is only as good as the sales of the books they have collaborated on in the past. The more successful the "Bio" on person X is, the more that Gost Writer Y can charge for their services to assist person Z on their biography, and the more likely that person Z (or manager of person Z) is to engage Ghost writer Y to assist on the project.
So, is the increase in player biographies hitting the market "early" due to pressure from Ghost Writers looking for work, and to enhance their CV's?
To flow on from the old fogie view, with bookshops and print in general struggling, will this be available as an eBook or whatever they are called?
I still like having paper and ink that I can feel and touch. Not so with the Junior Jarses. The old metric of a print run of x thousand will need to be merged with the "ebook" download sales/count as well.