9 March 2016
New Feature: Admin-Mandated Anonymous Link Expiration
Mandatory Anonymous Link Expiration is a new feature for SharePoint Online and OneDrive for Business. This feature is now available worldwide.
With this feature, administrators can now set a mandatory expiration limit for all anonymous links created in their company to help promote security and link hygiene. End users will be required to create links that match or are shorter than the stated value.
There is no default value for anonymous link expiration. To begin using this feature, use the SharePoint Online Management Shell using the “RequireAnonymousLinksExpireInDays” parameter. Click Additional Information below to learn more.
Set-SPOTenant -RequireAnonymousLinksExpireInDays 30
Microsoft referred to the following article in their update: Set-SPOTenant
The switch mentioned however doesn’t exist.
I found this blog from Drew Madelung very useful.