Who knows? Maybe she could just sell the ebook, then start taking pre-orders once it gets popular.
The majority of published authors don't really make much money at all. it's not uncommon to make less than $10k for a book that took over a year to write. Clearly they're not all in it for the money.
Maybe you wouldn't have as many mega successes, but are the current mega success really anything more than a product of the artificial scarcity caused by the publishing house gatekeepers. Again, who knows?