I guess since you’re going to have to give a password to someone, you can tell them not to do that.

Though I’m a bit confused why this is even needed. The sort of thing most people want accessible via a link, but only for certain people, tend to already have unpredictable URLs. I’m not sure how

https://gaggledocs.com/documents/aboevdowugwhoaofh

Is different from

https://protectmylink.xyz/owndoavwyagdo + a password

Especially when the original url is still publicly accessible on the internet.

Additionally, you normally have much better authorization options in the app you’re linking to.

I guess you get the benefit of a changeable link, unlike the canonical one? But then a link shortener is almost enough already.