The bio will probably be down within a few months, but your name on the directory might stay unless your replacement is very active with your clients. They're servicing the clients that you no longer are the best way they can. Let them.
So from your perspective, an employer should be able to use and/or profit off of it's former employee's identity and reputation indefinitely after that employee leaves?
I said that this can do more harm than good to the asker requests this while the company is still actively trying to redirect client requests.
If you can leave it long enough that you can approach them and they say "Oh, silly us, you're right! You left a while ago!" they will be much more receptive.
Like many things in business, this isn't about moral high-ground, it's about seeking the best outcome for yourself while offending as few people as possible.