The article itself mentions E Ink’s Kaleido 3 technology. I’m not really sure on the semantics of “e-ink” vs “e-paper”, but your take sounds good enough to me. I do know that E Ink makes a product internally (maybe also externally? idk) refered to as “ACeP”, which stands for “Advanced Color e-Paper”, so e-ink definitely classifies as a type of e-paper.