This article is talking about hacking existing E-ink ebook readers with custom made software/OS but why stop there?
Imagine an open ecosystem whereby we can have low power embedded systems running Linux OS or RTOS for plethora of computing/sensing/IoT useful applications on top low cost MPU that need rudimentary or sophisticated GUI e.g. dashboard, virtual buttons,etc [1].
[1] STM32MP2: ST’s first Linux capable 64-bit MPU with NPU, GPU and TSN
Have you seen the "Open Book" project?