Now, we should not blame the translator. I'll bet the "Royal We" was official policy under Pope Benedict XVI. And who could possibly have predicted the likes of humble Pope Francis?
It didn't take long for the translator to realize the "Royal We" runs against the spirit of Pope Francis. Just a few days later, the "Royal We" is gone.
1st person singular forms, such as ego, prospicio, and volo are used already on March 24, 2013, and the "Royal We" never reappears:
In response to your first tweet, Your Holiness, Fundo preces pro te, Papa Francisce, Domino Nostro...
"I pour out prayers for thee (2nd pers. sing. familiar form), Pope Francis, to our Lord..."
Update: there may be a new instance of the "Royal We" in a Papal Tweet. I explain that it is possible to interpret it otherwise.