I don't really think it abuses the term, since it doesn't require a backlight to display things, it is technically correct to call it e-paper. I also remember the people at Pebble discussing the differences between e-Ink and e-paper when it first came out. It's not like they hid how the Pebble's display worked.
Besides, an e-Ink screen would be a horrible experience given how the display gets used in the Pebble watch.
Besides, an e-Ink screen would be a horrible experience given how the display gets used in the Pebble watch.