Interesting! As lindy hop is the older name and jitterbug a newer, it makes sense to associate the word jitterbug with more 6 count moves.
It seems terminology in swing dances vary a lot. I am in nothern Europe, and d nice in the States... I always heard the terms were synonyms. Here, it seems if you say "lindy hop" you're inside our main swing community but if someone says "jitterbug" it means they have some vague memory of a TV shot of what people did on the dance floor here in the 50's. Not 100 % true, but the trend is obvious. Any jitterbug that was done here before the revival in the 80's is pretty much frowned upon by today's hardcore lindyhoppers, so I guess often lindy folks don't really want to relate to the name "jitterbug".