I don't recall ever hearing a Pioneer's deletion being announced at the Service Meeting. I've got a relative who recently stepped down due to her family circumstances changing drastically, and her name wasn't announced. Possibly because she may pioneer again after this familial situation works itself out. I know another younger pioneer who had to step down due to her parents gettting up in years, but she wasn't announced either. In fact, I didn't even know she was no longer pioneering.
At the same time, I know a pioneer who had a problem with alcohol, to the point of getting wasted in public, and she was temporarily deleted, but again I don't ever recall her name being announced. I know of a brother right now who recently got into some trouble, and he's now no longer a pioneer, however nothing's been announced yet, and that may be because the Service Committee is awaiting direction from the Branch.