Ann: Coburn Project Mining Services Contract Awarded, page-3

I wonder what the story is that has seen McMahon flicked from this contract, and no mention of the previous Ann in this one. See https://hotcopper.com.au/threads/ann-macmahon-appointed-as-preferred-mining-contractor-for-coburn.5369017/
There is no problem with a business changing direction to that previously announced, but to do so without explanation never sits well with me. It leaves one suspicious as to who exactly benefits from such changes away from a previously very solid looking decision.
I thought picking McMahon's was a smart decision as they bring scale and expertise from outside mineral sands and I expected them to set new performance benchmarks. Haven't checked out the new incumbent as just observing the facts of this change, not the merit, which the Ann only contains spin about that. Just observing...