I could potentially see technology like this being useful even for people without vision issues. The ability to read information from a display without needing to glance down at the watch would be great.
There are apps out there for phones and smartwatches that will vibrate text messages in Morse code. With any sort of determined study someone can pick up basic (~5 WPM) Morse code in about a week.
Unfortunately the best way to increase speed with Morse code is to learn to recognize entire letters as one object and not count "dots" and "dashes", which is much easier with sound over flashing lights or vibrations.