Not for Pages, Numbers, and Keynote. I am running the new Numbers just fine without a subscription. I don’t get the AI features for the subscription, but all of the existing features and functions are working just fine.
See Introducing Apple Creator Studio, an inspiring collection of creative apps - Apple, with this notice at the bottom:
Keynote, Pages, Numbers, and Freeform will remain free for all users to create, edit, and collaborate with others, including Apple Creator Studio subscribers. These apps will continue receiving updates, with the latest versions adopting the beautiful new visual design language with Liquid Glass on all platforms, and supporting the new windowing and menu bar improvements in iPadOS 26.