They can still run that app by signing it themselves with a developer account, although that's not a very convenient option. And no, this is still about what Google allows its employers to run on their corporate devices (and Apple now taking this right away from them), as users wouldn't be able to sign that app with enterprise certificate by themselves.

Google can make that app public.

Or stop abusing the terms of the enterprise certificates.

Since Gbus is presumably developed internally, what prevents the employees from installing the program via Xcode?

Not everyone at Google has a Mac? Nobody wants to reinstall GBus every 3 days?

Seven days.

Why would you have to reinstall it every 3 days?

IIRC dev certs expire quickly, by design

Free certificates expire after a week. Standard certificates obtained from a developer program membership last for a year.

Yup. However, at least you don't really need a Mac for that, as there are external tools to resign and install ipa files.

Probably something like this:

XX% of Google employees are non-technical

XX% of Google employees don't use Mac as their laptop platform

XX% of Google employees have a locked-down Mac that isn't allowed to run XCode or locally-compiled binaries because their job role isn't in Engineering

From what I understand, it actually is a public app:

https://www.tripshot.com/

https://itunes.apple.com/us/app/tripshot/id1007192056?mt=8

The employees would each have to spend $100 on a developer membership (sharing them is a good way to get more revokes).

No, that's not necessarily for loading an app on to your device. It's only necessary for broader distribution.

You can only sideload up to a certain number of apps (3 IIRC), only for seven days at a time, and only using certain APIs (cannot for example use notifications), all of which would pose serious limitations.

60,000+ employees makes this unrealistic.