I think that this particular limitation was copied from BAW documentation here: https://www.ibm.com/docs/en/baw/24.0.x?topic=postgresql-creating-databases and it warns you that BAW on traditional WAS can not support Advanced profile (bpm.de.type=Advanced in properties of BPMConfig, read: old capabilities from WebSphere Process Server) with PostgreSQL.
In that context this limitation does not apply to CP4BA as all "profiles" there are "standard" anyway.