As with any move, we're going through and weeding out material possessions we don't need anymore. And that goes for the archives as well. When I was younger I felt that old images, like fine wine, might become more valuable over time, and therefore it was imprudent to throw old pictures away, even when they didn't "make the cut". You never know about the future. That's a foundational principle of stock photography.
I benefitted from this philosophy a few times.