FAQ: Can I create an ARC for a previously published book?
Yes! Keep in mind that Booksprout's ARC feature was developed with ARCs in mind so it works best for them, but there's nothing stopping you from using it to get reviews on previously published books.
In fact, I totally recommend that you do so. The more ARCs you run, the more eyes you'll have on your writing, and the better chances you'll have of building a dedicated ARC team who will review your next book come launch day!