Technically this means that the EONIA is kept very close to the main policy rate in normal times. Through the adoption of fixed-rate full allotment in the longer-term refinancing operations the EONIA has been deviating from the main refinancing rate and has been closer to the deposit rate.
With a normalisation in financial markets the demand for excess liquidity is dropping, so that the withdrawal of non-standard measures can proceed. As a result the EONIA will ultimately return to levels around the main refinancing rate. Hence, the separation principle will be fully re-established. The monetary policy of the ECB is firmly grounded in this set of principles.