Fill Categories shows the total before big fills

Fill Categories now tells you how many products a large fill could add before it starts. When the categories you picked, times the products per category, come to 1,000 or more, you see the total and confirm first.

Large fills also pace themselves, so each category gets the number of products you asked for, and a second fill waits for the first to finish.

Find it under Store > Products > AI Tools > Fill Categories.