As can be seen in this link, the Musashigawa Beya confirms that Wakaichiro has retired. A rough translation of the text can be seen below:
[Wakaichiro Retirement Notice]
Wakaichiro has been working hard as a sumo wrestler for about three and a half years, but he has decided to retire and return to Houston.
We are very grateful to the warm welcome of Japanese people upon his arrival, and to the many people who supported him throughout his career.
If you have any difficulties in your future life, I hope you will use your experience in the sumo world to do your best.
Thank you all for your support of Wakaichiro!