Confidentiality and settlement privilege are not the same. Settlement privilege does not imply confidentiality. The existence of settlement privilege does not preclude refusal of confidentiality.
Settlement privilege is the presumptive inadmissibility in court of communication between the parties for the purpose of settlement.
See Union Carbide Canada Inc. v. Bombardier Inc., 2014 SCC 35 at paras. 37 & 39 (internal citations removed):
settlement privilege is an evidentiary rule that relates to the admissibility of evidence of communications. It does not prevent a party from disclosing information; it just renders the information inadmissible in litigation.
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A form of confidentiality is inherent in mediation in that the parties are typically discussing a settlement, which means that their communications are protected by the common law settlement privilege. But mediation is also a “creature of contract”, which means that parties can tailor their confidentiality requirements to exceed the scope of that privilege and, in the case of breach, avail themselves of a remedy in contract.
Confidentiality would be an additional constraint, only applicable by virtue of contract, or assumed voluntarily as a condition of further negotiation.