It has the same persistence if you haven't posted in awhile. I haven't posted a status in over a year, and the first few months I got countless notifications along the lines of "OMG YOU HAVEN'T POSTED IN ___ WEEKS! GET STARTED AGAIN".
Also, there's no reason for a "starter message" and prompt when I add a friend.
I'm sure once you do post something after a prolonged absence that they somehow highlight your post to everyone much more than it would normally appear.
I once went through a long tedious process of manually deleting posts and photos and after a while I got a very increased interaction on older images, not newer. Interaction from people who wouldn't normally comment, either.
I've been thinking of what to do with my next influential post (if I have one). Suicide awareness and help lines around the holidays could happen, or one mega life update with everything from the last however many months.
Also, there's no reason for a "starter message" and prompt when I add a friend.