We clone our announcements from the blueprint course into an empty associated course - and set them on timers associated with the cadence of the course. The avatar for these announcements is the letter U (not the image of the person who wrote the announcement). We've tried everything to get rid of the U and/or replace it with our logo (maybe this could a "default avatar feature"). In general, the feature request is to have the avatar of a cloned announcement revert to be the avatar of the person who wrote it.
We've submitted this as a bug -- but because it is expected behavior, Canvas has asked us to submit it as a feature request. Case #04113819
Here is an example from the announcement feed on our home page. There is no way to replace this image in the child course: