We used to provide an opt out to our customers for informtion sharing with nonaffiliates. Going forward, our intentions are not to share with nonaffiliates, therefore we decided to simplify our privacy policy.
Do we need to notify our existing customers of this change? We will, of course, send them an annual notice reflecting this change.

No, you do not need to send a revised policy since the change in your information sharing practices are more limited than before.