My suggestion would be to raise the matter as an early warning (its a matter that could delay Completion).
Clause 60.1.3 applies where the Employer fails to provide something he is required to provide and does not provide it by the date shown on the accepted programme.
If it was always the intention for the Employer to provide additional drawings after award and he has not done so by the programme date then yes it is a CE. It does however seem strange that this was the intention.
It seems more likely that the additional drawings would be a CE by way of being a change to the Works Information however I would need a clearer understanding of the specifics of the contract.