Shouldn't "the good news" be accepted?
that would be 'wamekuiambia habari nzuri'
? Swahili verbs only have a slot for one object prefix. You can't have two object prefixes at the same time.
Oh, I see: there is no infix for the direct object, just the indirect. Thank you!
What is wrong with "Wamekuambia habari njema?"