FWIW, many fitness watches that are designed for outdoor use (e.g. most Garmin or Amazfit models) still use transflective displays. They work flawlessly in bright sunlight, a backlight works well in the dark, and the battery life benefits compared to AMOLED or similar is an added bonus.
'Transflective' means that display has both backlight and reflective layer (Pebble used such technology). Playdate has no backlight, only reflective layer so it is 'reflective', not 'transflective'.