Arran, I first noticed a proliferation of these "ie" words about 30 years ago. Before that I can only recall "Connie" for a tram conductor. Names used to attract an "o" as in "John-o" and "Bottle-o" for the man who collected bottles, maybe from the call he used. Notable perhaps is the Welsh "Boy-o". John-o, Bill-o, Steve-o etc. are still used while Johnnie, Stevie etc. are less common.
Anyway I've always disliked the "ie" words a lot. I only use them as a joke. Some of us grew up.
Cheers Joy-O