Firstly, it is not clear, from the wording of the email, what the intention of the 'equipment list' is.
As the matter is considered to be an early warning by the Project Manager then hopefully you can discuss this at the risk reduction meeting.
There is no authority under 11.1 (19) for an instruction to be given which is provided at clause 14.3. An instruction from the PM may be valid, however, regardless of whether a clause is quoted, although you may wish to confirm authority under the contract.
Regardless of what the parties were aware of, the Works Information, as stated, determines the scope requirements for the project. If the email constitutes a change to the Works Information then this will need to be formally instructed and a compensation event notified accordingly, as you have stated to 'ensure its existence under the contract'.