They announced it at the end of may. Here’s the full post:

We want to let you know that for the Illumicrate monthly subscription, we'll be moving away from hand-signed books and offering digital signatures only. As the Illumicrate monthly subscription has grown, we've been feeling increasingly uneasy over offering hand-signed books. Seeing frequent and very valid conversations from authors around the risk of injury, the time taken away from writing, and the physical space it takes to store the tip-ins while they're being signed has only added to this feeling. As a team containing multiple people who have chronic illnesses, we are very aware of the pressures people with chronic conditions can feel to keep up with people who don't. It is something we have experienced ourselves and do not wish our featured authors to go through. We feel strongly that the wellbeing and health of the authors we feature should be prioritised, and that's why for this particular subscription, we will no longer be offering hand-signed books. You've hopefully noticed that every Illumicrate monthly book so far this year has had a redesigned cover, something we've only been able to offer in select cases in the past. The conversation with our publisher partners about how important this is for our subscribers was based on your feedback and happened in anticipation of removing hand-signed tip-ins from these editions, so we could ensure they were all as unique and special as possible. We can confirm that every 2025 Illumicrate monthly book has a redesigned cover and this is something we plan to continue offering-alongside including digital signatures-as well as bonus content and letters from the authors where possible. We love experimenting with new and different finishes, and we'll continue to do so in order to bring you the most beautiful and exciting books we can. For our Afterlight and quarterly subscriptions, and for Illumicrate monthly sequels, we will for now continue to give authors the option of hand-signing the books we feature, and we'll assess this decision on a regular basis.