This is inaccurate: ZIP 233: Network Sustainability Mechanism: Burning says:
burn_amount does not result in an output being produced in any chain value pool, and therefore from the point at which the transaction is applied to the global chain state,
burn_amountis subtracted from the issued supply. It is unavailable for circulation on the network at least through to the end of the block in which the transaction is mined. ZIP 234 specifies a potential mechanism by which the burned funds would again become available.
This is part of the problem with referring to the action of ZIP 233 as “burning”. It needs to be clear to users who make use of this mechanism whether it is possible for the “burned” funds to be reissued in the future. The current wording of this section clearly suggests that such reissuance is a possibility, and that ZIP 234 merely specifies one mechanism by which it might happen.
(I raise this point because I, along with other ZIP Editors, specifically objected to the use of “burning” as the term for this operation because in all other blockchain contexts I’m aware of, “burning” refers to an action that permanently reduces the supply.)