You may be confusing purchasing hardware and cloud subscription from the vendor producing the e ink display (Visionect) with the Project E ink device itself, which merely sources it's hardware from Visionect. The linked page is about the Project E ink device (https://projecteink.com/products/e-ink-newspaper-art-display...).
The only place that page mentions a subscription is in reference to news paper subscriptions.
This is a product page I looked at. Hard to interpret "Place & Play devices work on a subscription basis. Select a plan here." near "Add to cart" button.
The only place that page mentions a subscription is in reference to news paper subscriptions.