Does the IBP CI-DS change from JDBC to Websocket RFC only affect extracting data FROM IBP or does it also affect data being loaded INTO IBP?
it for sure affects the IBP inbound direction but I am technically not 100% sure about outbound though. The whole communication scenario you are supposed to set up on IBP side is an "inbound" only one. However it's not transparent for us as customer if the new access mode gets used in both ways.
Anyhow you mandatorily need to change your current setup in case not done yet and in case your IBP has been set up prior to version 2108, i.e. on the "outdated" JDBC technique.
Please compare following SAP notes as well:
3166596 Password Based Authentication Configuration Steps for WebSocket RFC
3152253 Certificate Based Authentication Configuration Steps for WebSocket RFC