We will be adding the ability for administrators to expire external users’ access to entire site collections after a mandatory expiration period, as we discussed at Ignite 2018. That feature will be rolling out in CY19Q3.Anonymous commented
This is exactly what i am asking for. An expiry date for a shared link would be useful, so that i can manage how long my students have access to a folder or file. I would not want students in year 9 accessing the same folder the following year.