You keep your rank until you have reached the next one, being Seducer at 1000.
2x the required amount of posts is not enough for the next rank. You need 3.16x the required amount.
Which is only odd because Caeli made it up, the next one is at 100k : )
I think she was just quoting Trieste, who pulled it from the forum info. I guess it's been altered since then.
EDIT: Forgot to check page 2 again :(