I talked to someone building related tech in the industry and E-Ink the company has a stranglehold on suppliers and leverages that to force compliance despite the patent nearing expiration (blocking anyone else from getting access to those suppliers).
The patent has allowed them to become entrenched and all current suppliers to depend on them. This will be hard to correct even with patent expiration.
I don't remember the specific details (unfortunately) and it's second hand info, but I was disappointed to hear it from someone more involved than I.