That statement does look like investment advice.
Would that be unlawful, in Japan? (I'm guessing it would be, in the US, Europe.)
"GOOG will go up."
"AMZN will go up."
"Oil futures will go up."
All would qualify as investment advice if coming from the mouth of anyone in a position of employment even remotely related to finance. So yeah, MtGox should definitely not have said that.