In short, no. There is no event generated for Read request sent from a Client device.
The reason is that the read request is handled by the BLE Stack automatically. The only thing to do is to update the Characteristic value by using CyBle_GattsWriteAttributeValue() API and appropriate attribute handler. Whenever the Read request arrives, the stack sends the latest value in its GATT DB (the one updated by application using the API) to the requesting device.
Thank you for your response and the information.