It is not used in the parts of Brazil I know (mostly RJ and MG). I know that Duolingo tries to include European Portuguese (even though it teaches Brazilian Portuguese) just as much as it tries to accept British English (even though it is based on American English). The problem is that currently the answer pool is still Brazilian/American biased.
I tried entering "sumo" as an answer to a few questions that accept "suco" and lost a heart every time. So it is probably best to answer "suco" for the time being but at the same time suggest "sumo" as an answer through the report problem button - eventually that will be accepted as well.