Ann: Board Changes, page-77

"While Idemitsu Australia remains highly supportive of the Company and its strategy, Mr Flanagan's departure has brought an end to the change of control undertaking previously provided, that under certain prescribed circumstances, it accept, reject or vote in a manner aligned with the Board in respect of a possible change of control transaction (refer ASX announcement dated 14 June 2023)"

Also in the Change in Substantial notice it states "Delta no longer has the ability to control the exercise of a right to vote and the exercise of a power to dispose of the shares, pursuant to aChange of Control Undertaking between Delta and Idemitsu"
It looks like Idemitsu was going to take control of Delta at some point in the future as part of coming on board as an insto if their decisions were misaligned with each other. Now, with CE coming onboard, it seems CE has revoked those rights from Idemitsu.
I personally can't see Idemitsu hanging around for long with CE at the helm of this ship now, as it seems they have been cut out from the decisions the board now makes under CE. There is some of the shrewdness quality showing on how CE operates. I am sure there is more to come from CE & co. That is how business works, need to be shrewd in business to survive, and CE is showing exactly that.