Google considers pretty much everything in hwops to be a trade secret. The point is to keep the specifics unknown as much as possible from competitors; the public at large's knowledge is just collateral damage in that fight.
And this one in particular is a high-ticket trade secret; it has been for decades, long before the AI push.
Power and water consumption number revelation goes directly to ceiling on maximum compute and relative compute efficiency. It's handing to every competitor on the planet (including China) "Hey, here's the raw situation on how far along we are on our total capacity to do anything."
... whether this should be a trade secret (since power and water are both shared resources with the surrounding community) is a reasonable question, but in the ecosystem where it is, Google having this data public and their competitors not is a problem.
If they are so good at it, they should push to make that the bare minimum and get to hold all future datacenter permits.
What benefit could competitors get from that information?