Yes, but where are the guarantees that you don't?
Just think from outsider's point of view: when he sees

�Announcer subclass: #Foo

what he will think first:
�- aha, this guy implements own kind of announcer
or
�- aha this guy reusing announcer
or
�- aha, this guy doing both things at the same time (a worst possible
alternative)

and how many abuses like that, he should see before making a logical conclusion:
�- aha.. this is the way how i should do as well.