change irule destined pool1 to pool2 while oneconnect is enabled in HTTP virtual server

Refer to: sol7964: Persistence may fail for subsequent requests on Keep-Alive connections:

If a OneConnect profile is associated with the virtual server, the BIG-IP system selects a pool member when the client-side connection is first established. When the response is complete, the BIG-IP system automatically detaches the server-side connection. When a subsequent request arrives on the same Keep-Alive connection, a new load balancing decision is made, using persistence information if it is available. When an HTTP client sends multiple requests within a single Keep-Alive connection, the BIG-IP system is able to load balance and persist each HTTP request individually, and sends each HTTP request to the appropriate destination server.

So essentially, yes. OneConnect will disconnect the server side connection between requests regardless of the client side keep-alive.