Source please. Not that even that would imply any other other authority, but still.
And that means what, exactly? The catholic church?
That's not authority, that's more or less an order to do these things.
The authority to proclaim a message hinges on actually truthfully proclaiming said message. If the math teacher says 2+2=5, and the student says 2+2=4, that just the roles should be switched, not that two and two make five. Or, in the case of the gospel, if the catholic church starts asking for money to shorten the time dead relatives spend in purgatorium, or burns anything and anyone threatening its authority. Or hey, what about making Charlemagne "Holy Roman Emperor" after he had forced people to convert to Christianity or be killed. The list is endless, too.
You know, stuff that seems rather basic in hindsight.. sadly, the reasons we now view such thing as barbaric and idiotic were mostly externally imposed on the Catholic Church, so no credit for that. Which is odd for an institution which is supposed to bring light into the world, or salt the soup, I forget which it was. If they have The Keys(tm), they sure fumbled sometimes.
Proclaiming good news to the poor and downtrodden, huh? Speaking truth in the face of power, instead of colluding with it, heh? I'm sorry, but it's hard to even discuss this seriously. I guess some are so steeped into the armpit juice of mama church that they just don't notice how hideous it looks from another perspective. I'd say the same about warmongering evangelicals in mega churches though, so don't think I have it in for the Catholics; just those, too.