It won't. Events wont happen in the middle of running code [1].
If the other three print functions are also async, the callbacks may be called in any order, and any interleaving, if they have more than one callback, but they won't be interrupting each other.
If the other print functions are not async, they will definitely complete before the news digest callback is called.
/L
[1] Unless someone is using a sync completer in a non-recommended way. In that case, it should be reported as a bug. Sync completers are intended to be used to turn one event turn into another without going back through the event loop, but the callbacks shouldn't be able to tell the difference.