I have always been under the impression that "protected" indeeds means "confirmed" - not "waitlisted".

Being waitlisted has close to zero value during irrops since any pax would be waitlisted.

IME "protected" can mean either of the following:

1) the concierge rebooks you onto a later flight
2) the concierge holds a confirmed seat on a later flight while maintaining your current reservation in case you do arrive in time