What makes you think that? There's a lot of data centers that sell you access to colocated Mac Mini's, they have added FileVault unlock via SSH in the boot process which also makes things easier. There's not that many reasons to run a Mac in the cloud unless you have some very specific Mac related workload.
https://wccftech.com/apples-private-cloud-compute-server-m5-...
There’s articles about them, Apple uses them internally for AI services. https://forums.macrumors.com/threads/photos-of-apples-own-ne...
Here's a leaked / rumor image of Apple servers themselves.
https://www.macrumors.com/2026/08/26/leaked-images-of-apple-...
https://www.macrumors.com/2026/08/26/leaked-images-of-apple-...
https://www.reuters.com/business/apple-begins-shipping-ai-se...
> [still claims there is no reason]
https://forums.macrumors.com/threads/photos-of-apples-own-ne...
Only if by "secret" you mean "announced in multiple press releases and a public event with federal, state, and local officials at its new sever factory in Houston."
https://www.apple.com/newsroom/2026/08/apple-opens-advanced-...
Plus they did sell rackmount servers for some time.